MLA

Commission, Iowa. Highway. Iowa, 1945 / Iowa State Highway Commission, Ames. Iowa State Highway Commission, 0AD. https://collections.library.yale.edu/catalog/15814638.

APA, 6th edition

Commission, I. H. (0 C.E.). Iowa, 1945 / Iowa State Highway Commission, Ames. [Road maps]. Iowa State Highway Commission, https://collections.library.yale.edu/catalog/15814638.