MLA

Backus, Isaac, 1724-1806. A great faith described and inculcated. Box 4, folder 1. 1805. https://collections.library.yale.edu/catalog/33530573.

APA, 6th edition

Backus, Isaac, 1724-1806. (["Box 4, folder 1"])(1805)[A great faith described and inculcated]. https://collections.library.yale.edu/catalog/33530573.