MLA

Salsbury, Nathan, 1846-1902. Salsbury family genealogical notes. Box 2, folder 55. n.d.. https://collections.library.yale.edu/catalog/17060017.

APA, 6th edition

Salsbury, Nathan, 1846-1902. (["Box 2, folder 55"])(n.d.)[Salsbury family genealogical notes]. https://collections.library.yale.edu/catalog/17060017.