MLA

Sully, Alfred, 1821-1879. Transcripts of military papers relating to Alfred Sully: 1842-70, n.d.. Box 6, folder 102-14. n.d.. https://collections.library.yale.edu/catalog/16703611.

APA, 6th edition

Sully, Alfred, 1821-1879. (["Box 6, folder 102-14"])(n.d.)[Transcripts of military papers relating to Alfred Sully: 1842-70, n.d.]. https://collections.library.yale.edu/catalog/16703611.