MLA

Sanborn Map Company, issuing body. Insurance Maps of Willimantic, Windham County, Connecticut. 1908. https://collections.library.yale.edu/catalog/11679624.

APA, 6th edition

Sanborn Map Company, issuing body. (1908). Insurance maps of Willimantic, Windham County, Connecticut. [Atlases--Connecticut--Willimantic--1908, Cadastral maps--Connecticut--Willimantic--1908, Fire insurance maps--Connecticut--Willimantic--1908]. https://collections.library.yale.edu/catalog/11679624.