MLA

H. D. (Hilda Doolittle), 1886-1961. "Eidolon". Box 33, folder 865. 1961. https://collections.library.yale.edu/catalog/17064223.

APA, 6th edition

H. D. (Hilda Doolittle), 1886-1961. (["Box 33, folder 865"])(1961)["Eidolon"]. https://collections.library.yale.edu/catalog/17064223.