Cite

Map of Williamstown, Mass. / compiled from town records and surveys by Alexander Walker, C.E.

MLA

Walker, Alexander. Map of Williamstown, Mass. / Compiled from Town Records and Surveys by Alexander Walker, C.E. s.n., 0AD. https://collections.library.yale.edu/catalog/15654656.

APA, 6th edition

Walker, A. (0 C.E.). Map of Williamstown, Mass. / compiled from town records and surveys by Alexander Walker, C.E. [Maps]. s.n., https://collections.library.yale.edu/catalog/15654656.