MLA

Wilson, Edmund, 1895-1972. Slapstick. Box 204, folder 5014. n.d.. https://collections.library.yale.edu/catalog/2005095.

APA, 6th edition

Wilson, Edmund, 1895-1972. (["Box 204, folder 5014"])(n.d.)[Slapstick]. https://collections.library.yale.edu/catalog/2005095.