MLA

Streeter, Thomas W. (Thomas Winthrop), 1883-1965. Agreement as to terms of duel between I.R. Lewis and W.H. Jack, San Felipe de Austin. Box 2, folder 81. 1832 Aug 4. https://collections.library.yale.edu/catalog/17437999.

APA, 6th edition

Streeter, Thomas W. (Thomas Winthrop), 1883-1965. (["Box 2, folder 81"])(1832 Aug 4)[Agreement as to terms of duel between I.R. Lewis and W.H. Jack, San Felipe de Austin]. https://collections.library.yale.edu/catalog/17437999.