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GEN BUS 360: Workplace Writing and Communication (Spring 2022)

Differentiating between Sources with the Same Author and Date

In-text parenthetical citations in APA use only the author’s last name and the publication year, but this can create confusion if you have multiple sources from the same author published in the same year. Use the following system to differentiate between such sources.


Two Sources with the Same Author and the Same Publication Year

Order citations on the References page from oldest to newest, and then identify the first (oldest) entry of the year with the letter “a” directly after the year; the second entry will be “b” and so on.


In-text Citation Example

Daniel Creel (2017b), a dietician and psychologist, suggested that being warm and empathetic can create positive relationships with people struggling with weight issues. Creel (2017a) further argued that dieticians should shift from seeing themselves as educators to guides, which can help alleviate frustration with noncompliant patients. 


References Page Entries

Creel, D. B. (2017a, January 13). Relinquishing your role as the food police. RD Lounge.

Creel, D. B. (2017b, November 30) Obesity: Communicating with respect. RD Lounge. 


Multiple Sources with the Same Author (Including Owners or Sponsors as Authors) and No Date

Order citations in alphabetical order, and then identify the first entry with the letter “a” and a hyphen directly after the n.d.; the second entry will be “b” and a hyphen, and so on. 

In-text Citation Example

Whole Foods expressed their belief in “long-term thinking” as a value for leaders (Whole Foods Market, n.d.–b), which corresponds with their branding as a company committed to organic products (Whole Foods Market, n.d.–c) and “environmental stewardship” (Whole Foods Market, n.d.–a).


References Page Entries

Whole Foods Market. (n.d.- a). Our core values. Retrieved December 15, 2019, from

Whole Foods Market. (n.d.- b). Our leadership principles. Retrieved December 3, 2019, from

Whole Foods Market. (n.d.- c). Your certified organic grocer. Retrieved November 30, 2019, from

Content Credit

Content on this page was created by the Business Communication team at the Wisconsin School of Business.