MLA

Stein, Gertrude, 1874-1946. Blood, Florence. Box 98, folder 1877-1878. 1908-21. https://collections.library.yale.edu/catalog/32342266.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 98, folder 1877-1878"])(1908-21)[Blood, Florence]. https://collections.library.yale.edu/catalog/32342266.