MLA

Sanborn Map Company, issuing body. Insurance Maps of Bristol, Hartford Co., Connecticut. 1921. https://collections.library.yale.edu/catalog/11040072.

APA, 6th edition

Sanborn Map Company, issuing body. (1921). Insurance maps of Bristol, Hartford Co., Connecticut. [Atlases, Bristol, Cadastral maps, Connecticut, Fire insurance maps, local]. https://collections.library.yale.edu/catalog/11040072.