Background material
MLA
Wharton, Edith, 1862-1937. Background material. Box 14, folder 388. n.d.. https://collections.library.yale.edu/catalog/17111098.
APA, 6th edition
Wharton, Edith, 1862-1937. (["Box 14, folder 388"])(n.d.)[Background material]. https://collections.library.yale.edu/catalog/17111098.