MLA

H. D. (Hilda Doolittle), 1886-1961. Aldington, Richard. Box 17, folder 566-71. 1953-61, n.d.. https://collections.library.yale.edu/catalog/10545548.

APA, 6th edition

H. D. (Hilda Doolittle), 1886-1961. (["Box 17, folder 566-71"])(1953-61, n.d.)[Aldington, Richard]. https://collections.library.yale.edu/catalog/10545548.