MLA

Phillips, Ulrich Bonnell, 1877-1934. Blacks working. Box 1, folder 5. Circa 1900-circa 1930. https://collections.library.yale.edu/catalog/10019895.

APA, 6th edition

Phillips, Ulrich Bonnell, 1877-1934. (["Box 1, folder 5"])(Circa 1900-circa 1930)[Blacks working]. https://collections.library.yale.edu/catalog/10019895.