FAQS

Section 8.19 (page 267) of the Publication Manual of the American Psychological Association (7th ed.) addresses this.

Basically, if you have more than one source by the same author, with the same publication year, you need to add letters a, b, c, d, etc. behind the year to help differentiate them from one another. The letters (a, b c....) are determined by the order of the sources on the reference page (alphabetically by title).

The letters are used in both the reference page and in-text and parenthetical citations.

Example of the original reference list items without differentiation (red and bold are there so you can more easily see):

Anderson, R. (2012). Chickens, dogs and frogs on your farm. Wetterling Brothers.

Smith, J. (2010). Chickens rule, dogs drool. Willemssen Publishing.

Smith, J. (2010). Frogs are better than toads. Hirning Publishing.

Zuber, K. (2011). Toads versus frogs. Rasmussen House Publishers.

The two Smith references need to be differentiated with letters behind their dates in the order they appear in the list. You will need to do this manually. NoodleTools will not do it for you.

Example (red color and bolding are there only so you can see them better):

Anderson, R. (2012). Chickens, dogs and frogs on your farm. Wetterling Brothers.

Smith, J. (2010a). Chickens rule, dogs drool. Willemssen Publishing.

Smith, J. (2010b). Frogs are better than toads. Hirning Publishing.

Zuber, K. (2011). Toads versus frogs. Rasmussen House Publishers.

Matching in-text citations for the body your paper will be:

(Smith, 2010a)  and (Smith, 2010b)

If you have no date, add a hyphen before the a and b, like this:

Smith, J. (n.d. -a). Bats http://...

Smith, J. (n.d. -b). Rats. http://...

For more information: https://apastyle.apa.org/style-grammar-guidelines/citations/basic-principles/same-year-author

Visit the APA Guide for additional APA information and resources.