MLA

Luhan, Mabel Dodge, 1879-1962. Jeffers, Robinson. Box 65, folder 1760. 1934-37, n.d.. https://collections.library.yale.edu/catalog/10268224.

APA, 6th edition

Luhan, Mabel Dodge, 1879-1962. (["Box 65, folder 1760"])(1934-37, n.d.)[Jeffers, Robinson]. https://collections.library.yale.edu/catalog/10268224.