MLA

Backus, Isaac, 1724-1806. Collected papers. box 9, folder 9. 1770 November 8–1770 November 13. https://collections.library.yale.edu/catalog/33571906.

APA, 6th edition

Backus, Isaac, 1724-1806. (["box 9, folder 9"])(1770 November 8–1770 November 13)[Collected papers]. https://collections.library.yale.edu/catalog/33571906.