MLA

Salsbury, Nathan, 1846-1902. Salsbury, Rachel Samuels. Box 3, folder 84-89. 1879-1915, n.d.. https://collections.library.yale.edu/catalog/2006000.

APA, 6th edition

Salsbury, Nathan, 1846-1902. (["Box 3, folder 84-89"])(1879-1915, n.d.)[Salsbury, Rachel Samuels]. https://collections.library.yale.edu/catalog/2006000.