MLA

Bierce, Ambrose, 1842-1914?. Route Maps : of a Journey from Fort Laramie, Dakota Terr. to Fort Benton, Montana Territory / by Ambrose Gwinett Bierce, 1866.. 1866. https://collections.library.yale.edu/catalog/17470648.

APA, 6th edition

Bierce, Ambrose, 1842-1914?. (1866)[Route Maps : of a Journey from Fort Laramie, Dakota Terr. to Fort Benton, Montana Territory / by Ambrose Gwinett Bierce, 1866.]. https://collections.library.yale.edu/catalog/17470648.