MLA

MacLeish, Archibald, 1892-1982. Origo, Iris. Box 19, folder 405. 1957-58. https://collections.library.yale.edu/catalog/17166962.

APA, 6th edition

MacLeish, Archibald, 1892-1982. (["Box 19, folder 405"])(1957-58)[Origo, Iris]. https://collections.library.yale.edu/catalog/17166962.