MLA

Loud, Lance, 1951-2001. Edith Massey. Box 1. undated. https://collections.library.yale.edu/catalog/16633024.

APA, 6th edition

Loud, Lance, 1951-2001. (["Box 1"])(undated)[Edith Massey]. https://collections.library.yale.edu/catalog/16633024.