MLA

Lord, James, 1922-2009. Tanning, Dorothea. Box 18, folder 199. 1973 October 27. https://collections.library.yale.edu/catalog/17332949.

APA, 6th edition

Lord, James, 1922-2009. (["Box 18, folder 199"])(1973 October 27)[Tanning, Dorothea]. https://collections.library.yale.edu/catalog/17332949.