MLA

Wharton, Edith, 1862-1937. "B" general. Box 23, folder 705. 1905-19, n.d.. https://collections.library.yale.edu/catalog/16761614.

APA, 6th edition

Wharton, Edith, 1862-1937. (["Box 23, folder 705"])(1905-19, n.d.)["B" general]. https://collections.library.yale.edu/catalog/16761614.