Cite

A history of New England...: Fragments of draft of work; draft of index

MLA

Backus, Isaac, 1724-1806. A history of New England...: Fragments of draft of work; draft of index. Box 4, folder 3. Undated. https://collections.library.yale.edu/catalog/33530594.

APA, 6th edition

Backus, Isaac, 1724-1806. (["Box 4, folder 3"])(Undated)[A history of New England...: Fragments of draft of work; draft of index]. https://collections.library.yale.edu/catalog/33530594.