MLA

Map, Sanborn, and issuing body Publishing Co. Insurance Maps of Stamford, Connecticut. 1888. https://collections.library.yale.edu/catalog/11633110.

APA, 6th edition

Map, S., & Publishing Co., issuing body. (1888). Insurance maps of Stamford, Connecticut. [Atlases--Connecticut--Stamford--1888, Cadastral maps--Connecticut--Stamford--1888, Fire insurance maps--Connecticut--Stamford--1888]. https://collections.library.yale.edu/catalog/11633110.