MLA

Johnson, A. B. (Alexander Bryan), 1786-1867. Letterbook of letters to Alexander Bryan Johnson. Box 3, folder 5. 1856 January-March. https://collections.library.yale.edu/catalog/32531177.

APA, 6th edition

Johnson, A. B. (Alexander Bryan), 1786-1867. (["Box 3, folder 5"])(1856 January-March)[Letterbook of letters to Alexander Bryan Johnson]. https://collections.library.yale.edu/catalog/32531177.