MLA

Lees-Milne, James, 1908-1997. Lees-Milne, Alvilde. Box 27, folder 1003. 1948-[80s]. https://collections.library.yale.edu/catalog/2007127.

APA, 6th edition

Lees-Milne, James, 1908-1997. (["Box 27, folder 1003"])(1948-[80s])[Lees-Milne, Alvilde]. https://collections.library.yale.edu/catalog/2007127.