To cite an oral history interview republished in a reader or textbook, treat the textbook as your source, since that is where you found the interview.
Say, for example, you wish to cite “Vina Deloria, Native American Author and Teacher,” an oral history interview that originally appeared in Studs Terkel’s American Dreams: Lost and Found, published by Pantheon Books in 1980 and then republished in The Studs Terkel Reader. To cite the republished version, list the name of the interviewee as the author, followed by the title of the interview. Then list the title of the reader or textbook as the title of the container and the textbook’s publication details:
Deloria, Vina. “Vina Deloria, Native American Author and Teacher.” The Studs Terkel Reader: My American Century, New Press, 1997, pp. 34-37.
Published 1 October 2019