MLA

Brush, George Jarvis, 1831-1912. Hagemann, Gustav (10). Box 2, folder 60. 1865-1866. https://collections.library.yale.edu/catalog/32513451.

APA, 6th edition

Brush, George Jarvis, 1831-1912. (["Box 2, folder 60"])(1865-1866)[Hagemann, Gustav (10)]. https://collections.library.yale.edu/catalog/32513451.