MLA

Map, Sanborn, and issuing body Publishing Co. Westport, Conn. 1885. https://collections.library.yale.edu/catalog/11676517.

APA, 6th edition

Map, S., & Publishing Co., issuing body. (1885). Westport, Conn. [Atlases--Connecticut--Westport--1885, Cadastral maps--Connecticut--Westport--1885, Fire insurance maps--Connecticut--Westport--1885]. https://collections.library.yale.edu/catalog/11676517.