MLA

Lynes, George Platt, 1907-1955. Datebook. Box 2, folder 12. 1949. https://collections.library.yale.edu/catalog/17156218.

APA, 6th edition

Lynes, George Platt, 1907-1955. (["Box 2, folder 12"])(1949)[Datebook]. https://collections.library.yale.edu/catalog/17156218.