A classification scheme for highway engineering :
adapted from the Library of Congress scheme by the Library staff of the Federal Works Agency and copied by the Colorado State Highway Department.

APA Citation

United States. Bureau of Public Roads. Library. (1949). A classification scheme for highway engineering: adapted from the Library of Congress scheme by the Library staff of the Federal Works Agency and copied by the Colorado State Highway Department. [Denver, Colo.: The Department].

MLA Citation

United States. Bureau of Public Roads. Library. A Classification Scheme for Highway Engineering: Adapted From the Library of Congress Scheme by the Library Staff of the Federal Works Agency And Copied by the Colorado State Highway Department. [Denver, Colo.: The Department], 1949.