MLA

Sanborn-Perris Map Co., issuing body. Unionville, Hartford Co., Conn. 1897. https://collections.library.yale.edu/catalog/11675406.

APA, 6th edition

Sanborn-Perris Map Co., issuing body. (1897). Unionville, Hartford Co., Conn. [Atlases--Connecticut--Unionville--1897, Cadastral maps--Connecticut--Unionville--1897, Fire insurance maps--Connecticut--Unionville--1897]. https://collections.library.yale.edu/catalog/11675406.