MLA

Purdy, James, 1914-2009. Olivier, Laurence. Box 3, folder 83. 1956. https://collections.library.yale.edu/catalog/32210552.

APA, 6th edition

Purdy, James, 1914-2009. (["Box 3, folder 83"])(1956)[Olivier, Laurence]. https://collections.library.yale.edu/catalog/32210552.