1938 official road map, North Dakota, South Dakota / [prepared for] Phillips Petroleum Company.
MLA
Company, H. M. Gousha. 1938 Official Road Map, North Dakota, South Dakota / [Prepared for] Phillips Petroleum Company. H.M. Gousha, 0AD. https://collections.library.yale.edu/catalog/15814740.
APA, 6th edition
Company, H. M. G. (0 C.E.). 1938 official road map, North Dakota, South Dakota / [prepared for] Phillips Petroleum Company. [Road maps]. H.M. Gousha, https://collections.library.yale.edu/catalog/15814740.