MLA

Rudge, Olga, 1895-1996. Writings: unidentified. Box 13, folder 533-534. n.d.. https://collections.library.yale.edu/catalog/17082119.

APA, 6th edition

Rudge, Olga, 1895-1996. (["Box 13, folder 533-534"])(n.d.)[Writings: unidentified]. https://collections.library.yale.edu/catalog/17082119.