MLA

Thurman, Wallace, 1902-1934. "Harlem", article about play by Thurman and Rapp, printed version, Detroit Free Press. Box 3, folder 41. 1929 May 12. https://collections.library.yale.edu/catalog/16732579.

APA, 6th edition

Thurman, Wallace, 1902-1934. (["Box 3, folder 41"])(1929 May 12)["Harlem", article about play by Thurman and Rapp, printed version, Detroit Free Press]. https://collections.library.yale.edu/catalog/16732579.