MLA

Company, H. M. Gousha. Continental Oil Co. Official Road Map, Colorado / H.M. Gousha Company ; Compliments of Continental Oil Co. The Company, 0AD. https://collections.library.yale.edu/catalog/15818465.

APA, 6th edition

Company, H. M. G. (0 C.E.). Continental Oil Co. official road map, Colorado / H.M. Gousha Company ; compliments of Continental Oil Co. [Road maps]. The Company, https://collections.library.yale.edu/catalog/15818465.