MLA

Van Thal, Herbert, 1904-1983. Parry, Edward Abbott. Box 1, folder 92. 1930 May 28. https://collections.library.yale.edu/catalog/16545996.

APA, 6th edition

Van Thal, Herbert, 1904-1983. (["Box 1, folder 92"])(1930 May 28)[Parry, Edward Abbott]. https://collections.library.yale.edu/catalog/16545996.