Map of the borough of Stonington, Conn. / surveyed and drawn by George D. Stanton and H. Clay Palmer.
MLA
Stanton, George D. Map of the Borough of Stonington, Conn. / Surveyed and Drawn by George D. Stanton and H. Clay Palmer. George D. Stanton and H. Clay Palmer, 1878. https://collections.library.yale.edu/catalog/16664832.
APA, 6th edition
Stanton, G. D. (1878). Map of the borough of Stonington, Conn. / surveyed and drawn by George D. Stanton and H. Clay Palmer. [Cadastral maps., Manuscript maps.]. George D. Stanton and H. Clay Palmer, https://collections.library.yale.edu/catalog/16664832.