Ordering Reference Entries With Same Author and Year in APA Style

Question:

How do I go about ordering entries in the reference list that have the same author and the same year of publication? I know that authors are listed in alphabetical order, and for the same author I should list entries chronologically, but picking one to go first seems random. And wouldn’t the citation be the same? Help!

How to arrange reference list entries when both author and year are the same

Short answer
In APA Style, when you have two or more sources written by the same author(s) that also have the same year of publication, follow these two steps:

1. Extend the alphabetization to the titles.
2. Add lowercase letters (a, b, c, etc.) to the year of publication to differentiate the entries when they are cited in the text. 

The details
It sounds easy—and it is—but beware of three things that might trip you up:

1. Messing up the spacing.
2. Adding letters when the year of publication is n.d.
3. Alphabetizing titles that include articles.

I cover all three items below!

The basics of alphabetizing reference list entries

1. Author last name

In APA Style, entries in a reference list are first alphabetized by the last name of the primary author. (Yes, there are some variations, such as by organization name. The principles I discuss here are the same, so for simplicity’s sake I refer only to author last name.)

2. Year of publication

If you have more than one source by the same author, entries are then arranged by year of publication. The order is always chronological, from earliest to most recent. Entries with no date go first, and entries in press go last. 

3. Title

If both the author name and the year of publication are the same, alphabetization proceeds to the title.

Let’s look at two sample entries where the author name and year of publication are the same.

In the examples, the author name and year of publication are the same, so to determine which entry comes first in the reference list, we look at the first word (or words) of the titles:

• “Learning” precedes “Phenomenographic” alphabetically.
• Thus, “Learning about phenomenography” would be listed first and would become 2005a.
• “Phenomenographic methods” would be listed second and would become 2005b.

Writing the references and citations

The reference list entries for the examples in the table would look like this:

Spacing and punctuating the added letters

When adding letters to a year of publication, here are some tips to keep in mind:

• Do not include spaces or hyphens: 2005a, 2005b, etc.
• However, n.d. (no date) is an exception. For readability, a hyphen is added before the letter: n.d.-a, n.d.-b. Notice the punctuation: N-dot-D-dot-hyphen-letter. 
• If you have more than 26 entries of this nature—in other words, you’ve added from a to z—double up the letters: 2005aa, 2005bb, etc.
• Bonus tip: This double lettering applies to appendices, too: After Appendix Z comes Appendix AA, Appendix BB, etc.
• We know you’re going to ask: What if you need to go past zz in your references or ZZ in appendices? The answer: Wha—?! Banish the thought and start simplifying!

Good luck with ordering your APA same author same year references!

We hope that this article has helped you with ordering references with the same author and year of publication in your paper, thesis, or dissertation. To ask us your questions, use the form at the bottom of our Ask the Editor page. We’d love to hear from you!