MLA

Sanborn Map Company, issuing body. Insurance Maps of New Britain, Hartford County, Connecticut. 1909. https://collections.library.yale.edu/catalog/11175781.

APA, 6th edition

Sanborn Map Company, issuing body. (1909). Insurance maps of New Britain, Hartford County, Connecticut. [Atlases, Cadastral maps, Connecticut, Fire insurance maps, local, New Britain]. https://collections.library.yale.edu/catalog/11175781.