MLA

Luhan, Mabel Dodge, 1879-1962. Karshan, Don. Box 22, folder 598. 1954 Apr. https://collections.library.yale.edu/catalog/17085355.

APA, 6th edition

Luhan, Mabel Dodge, 1879-1962. (["Box 22, folder 598"])(1954 Apr)[Karshan, Don]. https://collections.library.yale.edu/catalog/17085355.