MLA

Capt. B. L. Bonneville U.S.A, Ltih. of J. Bien, New York, New Yor. U.S.P.R.R. Exp. & Surveys. Lt. Warren's memoir. Plate I. Reduced map of the territory west of the Rocky Mountains by Capt. B.L. Bonneville U.S.A. 1837. Memoir to accompany the Map of the Territory of the United States...by Lieut. Gouverneur K. Warren...1859. Volume XI from Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi Rive. ca. 1855. https://collections.library.yale.edu/catalog/2015807.

APA, 6th edition

Capt. B. L. Bonneville U.S.A, & Ltih. of J. Bien, New York, New Yor. (["Memoir to accompany the Map of the Territory of the United States...by Lieut. Gouverneur K. Warren...1859. Volume XI from Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi Rive"])(ca. 1855)[U.S.P.R.R. Exp. & Surveys. Lt. Warren's memoir. Plate I. Reduced map of the territory west of the Rocky Mountains by Capt. B.L. Bonneville U.S.A. 1837]. https://collections.library.yale.edu/catalog/2015807.