MLA

Sanborn-Perris Map Co., issuing body. Thomaston, Litchfield Co., Conn. 1900. https://collections.library.yale.edu/catalog/11671982.

APA, 6th edition

Sanborn-Perris Map Co., issuing body. (1900). Thomaston, Litchfield Co., Conn. [Atlases--Connecticut--Thomaston--1900, Cadastral maps--Connecticut--Thomaston--1900, Fire insurance maps--Connecticut--Thomaston--1900]. https://collections.library.yale.edu/catalog/11671982.