MLA

Sanborn Map Company, issuing body. Insurance Maps of Derby and Shelton, New Haven County, Fairfield County, Connecticut. 1906. https://collections.library.yale.edu/catalog/11107697.

APA, 6th edition

Sanborn Map Company, issuing body. (1906). Insurance maps of Derby and Shelton, New Haven County, Fairfield County, Connecticut. [Atlases, Cadastral maps, Connecticut, Derby, Fire insurance maps, local, Shelton]. https://collections.library.yale.edu/catalog/11107697.