MLA

Barnitz, Albert Trovillo Siders, 1835-1912. Diaries. Box 4, folder 77-87. 1860-68 Apr. https://collections.library.yale.edu/catalog/17256944.

APA, 6th edition

Barnitz, Albert Trovillo Siders, 1835-1912. (["Box 4, folder 77-87"])(1860-68 Apr)[Diaries]. https://collections.library.yale.edu/catalog/17256944.