MLA

Company, Matthews-Northrup. Map of the New York Central and Hudson River Railroad and Its Connections / Wm. P. Northrup & Co., Map Engravers, Buffalo, N.Y. Matthews, Northrup & Co., 0AD. https://collections.library.yale.edu/catalog/15603773.

APA, 6th edition

Company, M.-N. (0 C.E.). Map of the New York Central and Hudson River Railroad and its connections / Wm. P. Northrup & Co., Map Engravers, Buffalo, N.Y. [Maps]. Matthews, Northrup & Co., https://collections.library.yale.edu/catalog/15603773.