MLA

Pryce-Jones, Alan, 1908-2000. Eyres-Monsell, Graham. Box 9, folder 400. 1937-86, n.d.. https://collections.library.yale.edu/catalog/17341190.

APA, 6th edition

Pryce-Jones, Alan, 1908-2000. (["Box 9, folder 400"])(1937-86, n.d.)[Eyres-Monsell, Graham]. https://collections.library.yale.edu/catalog/17341190.