MLA

Sanborn Map Company, issuing body. Ridgefield, Fairfield Co., Conn. 1901. https://collections.library.yale.edu/catalog/11594542.

APA, 6th edition

Sanborn Map Company, issuing body. (1901). Ridgefield, Fairfield Co., Conn. [Cadastral maps--Connecticut--Ridgefield--1901, Fire insurance maps--Connecticut--Ridgefield--1901]. https://collections.library.yale.edu/catalog/11594542.