MLA

Backus, Isaac, 1724-1806. Collected papers. box 8, folder 16. 1764 June–1764 July. https://collections.library.yale.edu/catalog/33555640.

APA, 6th edition

Backus, Isaac, 1724-1806. (["box 8, folder 16"])(1764 June–1764 July)[Collected papers]. https://collections.library.yale.edu/catalog/33555640.