MLA

Lees-Milne, James, 1908-1997. Kenworthy-Browne, John. Box 27, folder 1011. 1959, n.d.. https://collections.library.yale.edu/catalog/2007187.

APA, 6th edition

Lees-Milne, James, 1908-1997. (["Box 27, folder 1011"])(1959, n.d.)[Kenworthy-Browne, John]. https://collections.library.yale.edu/catalog/2007187.