Yellowstone National Park, Big Horn Mountains and adjacent territory / prepared in Office of Chief Engineer, Mil. Div. Mo. 1881 ; Emil Heubach, draughtsman.
MLA
Heubach, Emil. Yellowstone National Park, Big Horn Mountains and Adjacent Territory / Prepared in Office of Chief Engineer, Mil. Div. Mo. 1881 ; Emil Heubach, Draughtsman. Office of the Chief of Engineers, U.S.A., 1881. https://collections.library.yale.edu/catalog/15818384.
APA, 6th edition
Heubach, E. (1881). Yellowstone National Park, Big Horn Mountains and adjacent territory / prepared in Office of Chief Engineer, Mil. Div. Mo. 1881 ; Emil Heubach, draughtsman. [Maps]. Office of the Chief of Engineers, U.S.A., https://collections.library.yale.edu/catalog/15818384.
