MLA

Wilson, John C., approximately 1899-1961. Playscript. Box 1, folder 6. [1933]. https://collections.library.yale.edu/catalog/17290458.

APA, 6th edition

Wilson, John C., approximately 1899-1961. (["Box 1, folder 6"])([1933])[Playscript]. https://collections.library.yale.edu/catalog/17290458.