MLA

Harrington, Oliver W. (Oliver Wendell), 1912-1995. "Oh man! What are we goin' to buy us with this one Ahmed? The Rocky Mountains, Twentieth Century Fox, Wall Street or Madonna?". Box 34 (Oversize). undated. https://collections.library.yale.edu/catalog/33076520.

APA, 6th edition

Harrington, Oliver W. (Oliver Wendell), 1912-1995. (["Box 34 (Oversize)"])(undated)["Oh man! What are we goin' to buy us with this one Ahmed? The Rocky Mountains, Twentieth Century Fox, Wall Street or Madonna?"]. https://collections.library.yale.edu/catalog/33076520.