MLA

Ford, Julia Ellsworth, 1859-1950. Bangs, John Kendrick. Box 1, folder 4. 1902-1915. https://collections.library.yale.edu/catalog/17167801.

APA, 6th edition

Ford, Julia Ellsworth, 1859-1950. (["Box 1, folder 4"])(1902-1915)[Bangs, John Kendrick]. https://collections.library.yale.edu/catalog/17167801.