MLA

Sanborn Map Company, issuing body. Map of Central Business District of Bridgeport, Connecticut. 1904. https://collections.library.yale.edu/catalog/11036918.

APA, 6th edition

Sanborn Map Company, issuing body. (1904). Map of central business district of Bridgeport, Connecticut. [Cadastral maps--Connecticut--Bridgeport--1904, Fire insurance maps--Connecticut--Bridgeport--1904]. https://collections.library.yale.edu/catalog/11036918.