MLA

Hahn, Reynaldo, 1875-1947. Letters to Angèle Duglé. Box 1 | Folder 4. 1916-1921. https://collections.library.yale.edu/catalog/16686274.

APA, 6th edition

Hahn, Reynaldo, 1875-1947. (["Box 1 | Folder 4"])(1916-1921)[Letters to Angèle Duglé]. https://collections.library.yale.edu/catalog/16686274.