13 posts categorized "Digital Object Identifier (DOI)"

March 01, 2017

DOI Display Guidelines Update (March 2017)

Timothy McAdooby Timothy McAdoo

Do you know Crossref? Crossref is an organization “working to make content easy to find, link, cite, and assess” (Crossref, 2016). One of their services is to register digital object identifiers (DOIs), and we follow their guidelines for display of DOIs.DOI image-sm

Effective March 2017, Crossref has updated their DOI display guidelines, in part to ensure security (with https). For more details, see https://www.crossref.org/display-guidelines/ and https://www.crossref.org/blog/new-crossref-doi-display-guidelines-are-on-the-way/

Their new recommended format looks like this:


And here’s how that looks in an APA Style reference:

Morey, C. C., Cong, Y., Zheng, Y., Price, M., & Morey, R. D. (2015). The color-sharing bonus: Roles of perceptual organization and attentive processes in visual working memory. Archives of Scientific Psychology, 3, 18–29. https://doi.org/10.1037/arc0000014

Note the secure https and the simple url prefix doi.org.

Although we recommend moving to the new format, in APA Style manuscripts, we will be accepting the older formats (doi:10.1037/arc0000014 or http://dx.doi.org/10.1037/arc0000014) or the new format (https://doi.org/10.1037/arc0000014).

We recommend that you pick one format to use consistently throughout a reference list.

We will begin using the new format in our examples on this blog from this point forward. But, to clarify, in your manuscripts or papers, all of the following are currently considered correct APA Style:


Crossref. (2016). Annual report 15–16. Retrieved from https://www.crossref.org/pdfs/annual-report-2015-16.pdf

July 25, 2014

How to Use the New DOI Format in APA Style

Jeffby Jeff Hume-Pratuch

Have you noticed that references in most recently published journal articles end with a string of numbers and letters? That odd-looking item is the article’s digital object identifier (DOI), and it may just be the most important part of the reference. The DOI is like a digital fingerprint: Each article receives a unique one at birth, and it can be used to identify the article throughout its lifespan, no matter where it goes.

Fingerprint_WhorlDeveloped by a group of international publishers, the DOI System  provides a way to guarantee that digital copies of articles can remain accessible even if a journal changes its domain name or ceases publishing. DOIs are assigned and maintained by registration agencies such as CrossRef, which provides citation-linking services for scientific publishers.

In the sixth edition of the APA Publication Manual, DOIs are formatted according to the initial recommendations from CrossRef:

Herbst, D. M., Griffith, N. R.,  & Slama, K. M. (2014). Rodeo 
cowboys: Conforming to masculine norms and help-
seeking behaviors for depression. Journal of Rural
Mental Health, 38,
20–35. doi:10.1037/rmh0000008

The DOI prefix (10.1037, in the case of APA journals) is a unique number of four or more digits assigned to organizations; the suffix (rmh0000008) is assigned by the publisher and identifies the journal and individual article.
Recently, however, CrossRef changed the format of the DOI to a more user-friendly one in the form of a URL:

Herbst, D. M., Griffith, N. R.,  & Slama, K. M. (2014). Rodeo 
cowboys: Conforming to masculine norms and help-
seeking behaviors for depression. Journal of Rural
Mental Health, 38,
20–35. http://dx.doi.org/10.1037

As you can see, the DOI itself is the same (10.1037/rmh0000008), but it is preceded by  http://dx.doi.org/ to insure that it resolves into a working link. Because this change is recent and many publishers are still implementing the new CrossRef guidelines, either the old or the new DOI format is acceptable. But be sure not to mush them together! Here are some examples.


  • doi:10.1037/rmh0000008
  • http://dx.doi.org/10.1037/rmh0000008


  • http://doi:10.1037/rmh0000008
  • doi:http://dx.doi.org/10.1037/rmh0000008
  • Retrieved from http://dx.doi.org/10.1037/rmh0000008

Need more help with using DOIs? Try these posts from our blog:

August 17, 2012

Almost Published

Daisiesby Stefanie

Imagine you are writing a paper on a cutting-edge topic. A friend in the field passes along a manuscript on which she is working that is relevant to your work. Your advisor, on reading your draft, hands you his own manuscript, which takes a different approach to the material. He informs you that yesterday he submitted this very manuscript to a journal for publication. Then, on your favorite journal’s website, you stumble across a bunch of articles that will be published in a future issue but have yet to appear in print, all of which you would like to cite in your article. None of these sources have been published in physical books or journals, complete with page numbers, at least not yet; how do you create references for them?

Manuscript in Preparation
A manuscript for an article that is not yet finished, or that is in preparation, can be cited and referenced using the year the draft of the manuscript you read was written.

Kirk, J. T. (2011). Reprogramming the Kobayashi Maru test: 
     A tale of an inside job and the genius behind it. 
     Manuscript in preparation.

Manuscript Submitted for Publication
If the manuscript has been submitted for publication, again use the year the manuscript was written (not the year it was submitted) as your date. Also, do not provide the name of the journal or publisher to which the manuscript was submitted. If the manuscript is rejected on first submission, the author is free to submit the article elsewhere, where it could be accepted. If this happens while your own article is in preparation and if your reference names the first journal or publisher to which the material was submitted, your reference is not only out of date but misleading.

Castle, R. (2012). Shadowing a police officer: How to be unobtrusive
     while solving cases in spectacular fashion. Manuscript submitted 
     for publication.

As soon as that article is accepted for publication, the status changes to in press and you can include the name of the journal in the reference.

Castle, R. (in press). Shadowing a police officer: How to be unobtrusive
    while solving cases in spectacular fashion. Professional Writers’

Advance Online Publication
Now, onward into the brave new world of articles being available before they are available—in specific issues of print or online-only journals, that is. Definitions of advance online publication vary among journal publishers. Sometimes articles appearing in advance online publication databases have been edited, sometimes they have not. They may or may not have a DOI assigned. For many publishers, these articles are the version of record and thus are, technically, published, belying the title of this post.

Yet the question remains: How does one create references for advance online publication articles? Provide the author(s), year of posting, title of the article, name of the journal, the notation Advance online publication, and the DOI or the URL of the journal’s home page.

Muldoon, K., Towse, J., Simms, V., Perra, O., & Menzies, V. (2012). A
     longitudinal analysis of estimation, counting skills, and 
     mathematical ability across the first school year. Developmental 
     Psychology. Advance online publication. doi:10.1037/a0028240

As your article is heading toward submission and publication, keep following up on your references that are moving through their own publication processes, and update them as you are able. If possible, refer to the final versions of your sources.

Have other questions about preprint publication sources? Comment here or e-mail styleexpert@apastyle.org!


May 17, 2012

Missing Pieces: How to Write an APA Style Reference Even Without All the Information

Chelsea blog 2by Chelsea Lee

Most APA Style references are straightforward to write—the guidance and examples in Chapter 7 of the Publication Manual and on this blog make that possible. We’ve written a good deal about the architecture of a generic reference (the four basic pieces of author, date, title, and source). Sometimes, however, one or more of those pieces is missing, and writing the reference can get more difficult. This post will help you adapt the classic APA Style reference template to fit any situation where information might be missing, as well as show you how to create the corresponding in-text citations for those references. 

The table below shows how to write an APA Style reference when information is missing. It is also available for download as a PDF.

What’s missing?


Reference template

Position A

Position B

Position C

Position D

Nothing—all pieces are present

List information in the order of author, date, title (with description in square brackets if necessary for explanation of nonroutine information), and source

Author, A. A.


Title of document [Format].


Title of document [Format].

Retrieved from http://xxxxx


Retrieved Month Day, Year, from http://xxxxx


Location: Publisher.



Author is missing

Substitute title for author; then provide date and source

Title of document [Format].


Title of document [Format].



Date is missing

Provide author, substitute n.d. for no date, and then give title and source

Author, A. A.


Title of document [Format].


Title of document [Format].

Title is missing

Provide author and date, describe document inside square brackets, and then give source

Author, A. A.


[Description of document].

Author and date are both missing

Substitute title for author and n.d. for no date; then give source

Title of document [Format].


Title of document [Format].



Author and title are both missing

Substitute description of document inside square brackets for author; then give date and source

[Description of document].



Date and title are both missing

Provide author, substitute n.d. for no date, describe document inside square brackets, and then give source

Author, A. A.


[Description of document].

Author, date, and title are all missing

Substitute description of document inside square brackets for author, substitute n.d. for no date, and then give source

[Description of document].



Source is missing

Cite as personal communication (see §6.20) or find a substitute





Title Variations

As shown in the table, the title of a document is only sometimes italicized, depending on the independence of the source. That is, do italicize the title of a document that stands alone (books, reports, etc.), but do not italicize the title of a document that is part of a greater whole (chapters, articles, etc., which are part of edited books or journals, respectively). Also do not italicize the titles of software, instruments, and apparatus (see §7.08 in the Publication Manual). If you have trouble determining whether something stands alone (such as for a document on a website), choose not to italicize. For examples and more explanation, see the blog post on capitalization and formatting of reference titles in the reference list.

Source Variations

As shown in the Position D column of the table, the source part of a reference list entry can vary as well. It should reflect either a retrieval URL (for online documents without DOIs), a publisher location and name (for print sources), or a DOI (for any document that has one, whether print or online). It is not usually necessary to include a retrieval date for online sources; one should be provided only if the source is likely to change over time, such as with an unarchived wiki page.

Sometimes source information is incomplete but with a little detective work you can find what you need; for example, if you know a publisher name but not its location, you can research the publisher to find the location. Even sources of limited availability can be cited in APA Style, including unpublished and informally published works (see §7.09) and archival documents and collections (see §7.10).

Note, however, that it is not possible to write a traditional APA Style reference if source information is truly missing. The purpose of an APA Style reference is to provide readers with information on how to locate the source that you used, and if you cannot tell them how to do so, you either have to find a substitute or cite the source as personal communication (see §6.20 in the Publication Manual).

Creating In-Text Citations

Create an in-text citation for any reference by using the pieces from Positions A and B in the table above. For most references, this will be the author and date (Author, date). For titles in Position A, use italics for works that stand alone (Title of Document, date) and quotation marks for works that are part of a greater whole (“Title of Document,” date). Retain square brackets for descriptions of documents in Position A ([Description of document], date). For examples and more explanation, see our post on formatting and capitalization of titles in the text.  

We hope this guide to missing pieces will help you as you create your APA Style references.

January 13, 2012

APA Style Interactive Learning

AnneGasqueAnne Gasque

Have you ever had the urge to read the Publication Manual from beginning to end? We thought not. 

It takes a special kind of stamina and devotion to approach a manual of writing guidance and style rules with the excitement a person might bring to, say, John Grisham’s latest legal thriller. To help you find your way in the manual, we’ve created an interactive online course. This course, available for continuing education credit, provides a comprehensive tour of the guidance in the Publication Manual

Basics of APA Style: An Online Course follows the organization of the manual and offers an in-depth overview of the types of articles used in psychological and social research, manuscript elements, heading style, reducing bias in language, punctuation, capitalization, italics, numbers, tables, figures, citing references in text, creating a reference list, and reference templates and examples. Many of the sections in the course include relevant examples to provide context, and each section ends with two or three review questions to help you learn as you go along. The course ends with 20 assessment questions and offers 4 CE credits upon successful completion. We hope you find the course a helpful tool for learning APA Style!

If you would like a broader less detailed overview of APA Style, we offer a free tutorial, The Basics of APA Style, which shows you how to structure and format your work, recommends ways to reduce bias in language, identifies how to avoid charges of plagiarism, shows how to cite references in text, and provides selected reference examples.

June 03, 2011

How Do You Cite an E-Book (e.g., Kindle Book)?

Chelsea blog 2

by Chelsea Lee

E-books come in a variety of formats (e.g., Kindle, Adobe Digital Editions, EPub, HTML, and more) and can be read on a variety of devices (e.g., e-readers like the Kindle, Nook, and Sony Reader, as well as on personal computers and mobile devices through online portals such as NetLibrary, ebrary, and Google Books). This post shows how to cite any e-book in APA Style.

Reference List Entries

The reference list entry for a whole e-book should include elements of author, date, title (with e-reader book type in square brackets if applicable; italicize the title but not the bracketed material), and source (URL or DOI):

Author, A. A. (Year). Title of book [E-reader version, if applicable]. Retrieved from http://xxxxx

Author, A. A. (Year). Title of book [E-reader version, if applicable]. doi:xxxxx

  • If the book was read or acquired through an online library (e.g., Google Books, ebrary, NetLibrary) and not on an e-reader device, omit the bracketed information from the reference.

The reference list entry for a chapter in an edited e-book should be written as follows:

Author, A. A. (Year). Title of chapter. In B. B. Editor (Ed.), Title of book [E-reader version, if applicable] (pp. xxx–xxx). Retrieved from http://xxxxx

Author, A. A. (Year). Title of chapter. In B. B. Editor (Ed.), Title of book [E-reader version, if applicable] (pp. xxx–xxx). doi:xxxxx

  • If the e-book chapter does not have page numbers, omit that part of the reference.
  • To determine whether you need to cite the whole book or just a chapter, please see this post

In-Text Citations

For in-text citations of paraphrased material, provide the author and date, as for any APA Style reference. To cite a direct quotation, also provide page numbers if the e-book has page numbers. If there are no page numbers, you can include any of the following in the text to cite the quotation (see section 6.05 of the Publication Manual, pp. 171–172):

  • a paragraph number, if provided; alternatively, you can count paragraphs down from the beginning of the document; 
  • an overarching heading plus a paragraph number within that section; or 
  • an abbreviated heading (or the first few words of the heading) in quotation marks, in cases in which the heading is too unwieldy to cite in full.

A Note on Kindle Page Numbers and Location Numbers 

As of March 2011, many Kindle books now have real page numbers that correspond to those in print editions (as far as we know, this applies only for Kindle third generation products and going forward). These real page numbers are appropriate to use in academic citation (as are the page numbers of other paginated e-books). Kindle "location numbers," however, should not be used in citations because they have limited retrievability. Instead, for any e-book without page numbers, APA recommends the method described above for citations of directly quoted material.

See these links for further discussion of Kindles, e-books and e-book chapters, and citing unpaginated material, and see Publication Manual section 7.02 (pp. 202–205) for more examples.

January 28, 2010

The Generic Reference: Where

Jeffby Jeff Hume-Pratuch

This post is part of an ongoing series about how references work. It began with an introduction to the generic APA Style reference and posts on the author or “who” element, the date or “when” element, and the title or “what” element. Upcoming posts will cover adding supplementary information in brackets and mixing and matching elements of example references.

The last generic element in an APA reference is where a reader should go to locate the reference you used. (An alternate label for this element might be how—as in, “How can I locate that source?”)


For journals, newsletters, and magazines, the primary locator element is the volume number. It goes after the periodical’s title, in italics, and the article’s page range follows:

Elk, A. (1972a). My theory on brontosauruses. Journal of the

 All-England Summarize Proust Competition, 31, 12–27.


If (and only if) the journal is one that restarts the page numbering at 1 for each issue, include the issue number in parentheses after the volume number:

Elk, A. (1972b). The other theory on brontosauruses. Journal of the 

 All-England Summarize Proust Competition, 31(4), 47–50.


Note that if the issue number is used, it is in roman (i.e., not italic) type, as is the comma following it.

Books, Reports, and So Forth

Give the name and location of the publisher (city and state or, outside the United States, city and country) for books, reports, brochures, and other nonperiodical publications.

Gumby, T. F. (1972). The brain specialist. Cambridge, England: 


Note that the name of the publisher is given in as brief a form as possible. Eliminate words such as Publishers, Co., and Inc., and use only the surname for publishing houses that are named after persons (e.g., Erlbaum, not Lawrence Erlbaum; Wiley, not John Wiley). The names of universities, associations, and so forth are given in full.

The “well-known city rule” is no longer in effect, so the state (or country, for non-U.S. publishers) is included for all publishers. However, there is one exception to this rule: If the publisher is a university whose name includes the name of the state, don’t repeat the state in the publisher location.

Clark, D. T., & Schoomaker, P. J. How not to be seen. Tampa:

 University of Florida.


Electronic Sources

The digital object identifier (DOI) is the new gold standard for locating electronic publications. Through the magic of international concordats and computer programming, it will get you to the online version of the article every time, even if the publisher has changed Web addresses. Over the past few months we have devoted considerable space on the blog to the use (and the pros and cons) of DOIs, so I’ll simply point you to Chelsea's DOI primer and handy flowchart for guidance on when to use DOI versus URL. You may also want to check out Tim's video on how to find those pesky DOIs, and Paige's discussion of document URL versus homepage URL.

Odd Cases

Do you have a locator problem that stumps you? Post it here and we’ll try to figure it out!

December 10, 2009

How to Find a DOI

Timothy.mcadoo by Timothy McAdoo

Ever had trouble finding a DOI? In the video below, we demonstrate how to find a DOI in a variety of ways: from an article’s record in APA PsycINFO (on a number of vendor platforms), from an article itself (hard copy version or electronic), or from CrossRef’s Simple Text Query form.

We hope this visual demonstration is helpful. Are there other tutorials about APA Style that you’d like to see? Let us know!

P.S. For more detailed background information on DOIs, see Chelsea’s recent DOI primer. And for information about using DOIs and URLs in your references, don’t miss the DOI and URL flowchart!

Edit: The original DOI video has been replaced with an updated (March 30, 2016) version. A larger version of this tutorial, with a navigation menu option, is available here.

September 24, 2009

What to Use—The Full Document URL or Home Page URL?

Paige-for-web-site 75x75

by Paige Jackson

Following on from Annie’s post yesterday on URLs, today I wanted to share some tips that might help in deciding what to use when. With the increasing predominance of electronic publishing, it’s a challenge to know how best to cite documents you find online. The DOI is the gold standard, and eventually all documents will have their own DOIs. In the meantime, it’s not always easy to know what to do. If you find a document on the Internet (but not from a database) that you want to cite for which there is no DOI, is it better to cite the full document URL or the publisher home page URL?

The question to ask before deciding which to include is, Which will be most helpful to the reader in locating the document? The following are some instances when the homepage URL would be most helpful (all examples refer to Chapter 7 in the Publication Manual):

  • Subscription wall—If the document is available online only by subscription, the document URL would not be accessible by nonsubscribers. The homepage URL, however, lets the reader know who the publisher is and therefore what databases the reader might look to to access the document.
  • Unstable document URL—If the publisher is one for which document URLs are subject to change, the home page URL is more likely to be helpful (see Examples 11 and 19a).

In the following cases, the full document URL is likely to take the reader to the source more reliably:

  • Publisher website that’s difficult to search—Some publisher homepages—such as those of government agencies or nongovernmental organizations—can be difficult to search, so citing the full URL for a document that takes the reader directly to the document may save time (see Examples 9, 31, and 33).
  • Message posted to a blog or other online forum—Similarly, it can be difficult to locate a particular message on a blog website, so providing the URL that will lead the reader to the message would be the best choice (see Examples 74–77).

This list is not exhaustive—we hope it will give a sense of factors that should guide your decision. A URL is imperfect in pointing the reader to an electronic source, but for many sources, it’s the best we can do. So don’t belabor the issue—make an informed guess as to whether the publisher home page URL or the full document URL is more likely to lead the reader to the document in question, and move on!

September 22, 2009

A DOI and URL Flowchart

Chelsea blog

by Chelsea Lee

Yesterday I talked about the basics of DOIs. Today I'll be unveiling a flowchart about using DOIs and URLs in your references.

The most common questions we have gotten at APA since the introduction of the 6th edition of the Publication Manual have to do with using DOIs, URLs, and database information in reference citations. We on the blog team have done our best to analyze what the manual has to say about this matter, and the flowchart below illustrates the principles at work.

Click on the image below to see a larger version of the flowchart, or you can download a PDF of the flowchart (with hyperlinks to CrossRef) here: Download DOI and URL Flowchart

DOI and URL Flowchart_revised 922

We hope that the flowchart will be helpful to you. Stay tuned for tomorrow, when Annie will be sharing a blog on the nebulous nature of URLs.

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