MLA

Richardson, Dorothy M. (Dorothy Miller), 1873-1957. Kirkaldy, Peggy. Box 1, folder 14-17. 1928-31. https://collections.library.yale.edu/catalog/15237736.

APA, 6th edition

Richardson, Dorothy M. (Dorothy Miller), 1873-1957. (["Box 1, folder 14-17"])(1928-31)[Kirkaldy, Peggy]. https://collections.library.yale.edu/catalog/15237736.