MLA

Company, H. M. Gousha. 1937 Road Map, Idaho. H.M. Gousha, 1937. https://collections.library.yale.edu/catalog/15818347.

APA, 6th edition

Company, H. M. G. (1937). 1937 road map, Idaho. [Road maps]. H.M. Gousha, https://collections.library.yale.edu/catalog/15818347.