MLA

Sanborn Map Company, issuing body. Rockville, Tolland County, Connecticut. 1921. https://collections.library.yale.edu/catalog/11595820.

APA, 6th edition

Sanborn Map Company, issuing body. (1921). Rockville, Tolland County, Connecticut. [Atlases--Connecticut--Rockville--1921, Cadastral maps--Connecticut--Naugatuck--1921, Fire insurance maps--Connecticut--Rockville--1921]. https://collections.library.yale.edu/catalog/11595820.