MLA

Linton, W. J. (William James), 1812-1897. Forster, John. Box 1, folder 46. 1856 February 4. https://collections.library.yale.edu/catalog/17327096.

APA, 6th edition

Linton, W. J. (William James), 1812-1897. (["Box 1, folder 46"])(1856 February 4)[Forster, John]. https://collections.library.yale.edu/catalog/17327096.