MLA

Backus, Isaac, 1724-1806. volume 13. Box 1, folder 10. 1797 January 1–1802 December 31. https://collections.library.yale.edu/catalog/33297948.

APA, 6th edition

Backus, Isaac, 1724-1806. (["Box 1, folder 10"])(1797 January 1–1802 December 31)[volume 13]. https://collections.library.yale.edu/catalog/33297948.