Wilder on South American trip
MLA
Wilder, Thornton, 1897-1975. Wilder on South American trip. Box 150, folder 3579. 1941. https://collections.library.yale.edu/catalog/2037296.
APA, 6th edition
Wilder, Thornton, 1897-1975. (["Box 150, folder 3579"])(1941)[Wilder on South American trip]. https://collections.library.yale.edu/catalog/2037296.