Map of the United States showing Military Posts and Principal Lines of Communication / Prepared by direction of the Secretary of War in the Office of the Chief of Engineers U.S.A.
MLA
Map of the United States Showing Military Posts and Principal Lines of Communication / Prepared by Direction of the Secretary of War in the Office of the Chief of Engineers U.S.A. , 0AD. https://collections.library.yale.edu/catalog/15603781.
APA, 6th edition
Map of the United States showing Military Posts and Principal Lines of Communication / Prepared by direction of the Secretary of War in the Office of the Chief of Engineers U.S.A. (0 C.E.). [Maps]. , https://collections.library.yale.edu/catalog/15603781.
