MLA

Sanborn-Perris Map Co., issuing body. Insurance Maps of Norwalk, Fairfield County, Connecticut. 1901. https://collections.library.yale.edu/catalog/11580356.

APA, 6th edition

Sanborn-Perris Map Co., issuing body. (1901). Insurance maps of Norwalk, Fairfield County, Connecticut. [Atlases--Connecticut--Norwalk--1901, Cadastral maps--Connecticut--Norwalk--1901, Fire insurance maps--Connecticut--Norwalk--1901]. https://collections.library.yale.edu/catalog/11580356.