MLA

Sanborn Map Company, issuing body. Insurance Maps of Bridgeport, Connecticut., Insurance Maps of Bridgeport, Connecticut: [Additional Sheets]. 1918. https://collections.library.yale.edu/catalog/11687425.

APA, 6th edition

Sanborn Map Company, issuing body. (1918). Insurance maps of Bridgeport, Connecticut., Insurance maps of Bridgeport, Connecticut: [Additional sheets]. [Annotations (Provenance)--19th century.--CtY-BR, Atlases--Connecticut--Bridgeport--1913, Cadastral maps--Connecticut--Bridgeport--1913, Fire insurance maps--Connecticut--Bridgeport--1913]. https://collections.library.yale.edu/catalog/11687425.