MLA

Kilpatrick, Jack Frederick (1915-1967). "Mary" (Meli Hidasgi). Letter regarding plans for Christmas, to Tsesini Awigadoga. Box 1, folder 12. 1938. https://collections.library.yale.edu/catalog/15491322.

APA, 6th edition

Kilpatrick, Jack Frederick (1915-1967). (["Box 1, folder 12"])(1938)["Mary" (Meli Hidasgi). Letter regarding plans for Christmas, to Tsesini Awigadoga]. https://collections.library.yale.edu/catalog/15491322.