MLA

Map, Sanborn, and issuing body Publishing Co. Putnam, Connecticut. 1887. https://collections.library.yale.edu/catalog/11594405.

APA, 6th edition

Map, S., & Publishing Co., issuing body. (1887). Putnam, Connecticut. [Atlases--Connecticut--Putnam--1887, Cadastral maps--Connecticut--Putnam--1887, Fire insurance maps--Connecticut--Putnam--1887]. https://collections.library.yale.edu/catalog/11594405.