MLA

Benét, William Rose, 1886-1950. Pearson, Norman Holmes. Box 34, folder 1321-1322. 1936-1950, undated. https://collections.library.yale.edu/catalog/10167564.

APA, 6th edition

Benét, William Rose, 1886-1950. (["Box 34, folder 1321-1322"])(1936-1950, undated)[Pearson, Norman Holmes]. https://collections.library.yale.edu/catalog/10167564.