MLA

Sanborn Map Company, issuing body. Old Saybrook, Middlesex County, Connecticut. 1933. https://collections.library.yale.edu/catalog/11580678.

APA, 6th edition

Sanborn Map Company, issuing body. (1933). Old Saybrook, Middlesex County, Connecticut. [Atlases--Connecticut--Old Saybrook--1933, Cadastral maps--Connecticut--Old Saybrook--1933, Fire insurance maps--Connecticut--Old Saybrook--1933]. https://collections.library.yale.edu/catalog/11580678.