MLA

Sanborn Map Company, issuing body. Insurance Maps of Torrington, Litchfield Co., Connecticut. 1915. https://collections.library.yale.edu/catalog/11674898.

APA, 6th edition

Sanborn Map Company, issuing body. (1915). Insurance maps of Torrington, Litchfield Co., Connecticut. [Atlases--Connecticut--Torrington--1915, Cadastral maps--Connecticut--Torrington--1915, Fire insurance maps--Connecticut--Torrington--1915]. https://collections.library.yale.edu/catalog/11674898.