Cite

Pennsylvania Railroad : Great Trunk Line and U.S. Mail Route.

MLA

Allen, Lane, and Scott. Pennsylvania Railroad : Great Trunk Line and U.S. Mail Route. Allen, Lane & Scott, 1880. https://collections.library.yale.edu/catalog/15603758.

APA, 6th edition

Allen, L., & S. (1880). Pennsylvania Railroad : Great Trunk Line and U.S. Mail Route. [Maps]. Allen, Lane & Scott, https://collections.library.yale.edu/catalog/15603758.