MLA

H. D. (Hilda Doolittle), 1886-1961. Hart, Ellen. Box 10, folder 350. 1945-61. https://collections.library.yale.edu/catalog/17064192.

APA, 6th edition

H. D. (Hilda Doolittle), 1886-1961. (["Box 10, folder 350"])(1945-61)[Hart, Ellen]. https://collections.library.yale.edu/catalog/17064192.