MLA

Ficke, Arthur Davison, 1883-1945. "Ed Campbell": typescript, original, corrected, signed. Box 42, folder 1307. 1939 Feb 7. https://collections.library.yale.edu/catalog/17419050.

APA, 6th edition

Ficke, Arthur Davison, 1883-1945. (["Box 42, folder 1307"])(1939 Feb 7)["Ed Campbell": typescript, original, corrected, signed]. https://collections.library.yale.edu/catalog/17419050.