MLA

Backus, Isaac, 1724-1806. Collected papers. box 9, folder 24. 1772 February. https://collections.library.yale.edu/catalog/33578557.

APA, 6th edition

Backus, Isaac, 1724-1806. (["box 9, folder 24"])(1772 February)[Collected papers]. https://collections.library.yale.edu/catalog/33578557.