MLA

Richardson, Dorothy M. (Dorothy Miller), 1873-1957. DECEMBER: typescript 3 p.. Box 8, folder 146. n.d.. https://collections.library.yale.edu/catalog/16495625.

APA, 6th edition

Richardson, Dorothy M. (Dorothy Miller), 1873-1957. (["Box 8, folder 146"])(n.d.)[DECEMBER: typescript 3 p.]. https://collections.library.yale.edu/catalog/16495625.