MLA

Sanborn Map Company, issuing body. Insurance Maps of Southington, Hartford County, Connecticut. 1906. https://collections.library.yale.edu/catalog/11624104.

APA, 6th edition

Sanborn Map Company, issuing body. (1906). Insurance maps of Southington, Hartford County, Connecticut. [Atlases--Connecticut--Southington--1906, Cadastral maps--Connecticut--Southington--1906, Fire insurance maps--Connecticut--Southington--1906]. https://collections.library.yale.edu/catalog/11624104.