Collins, J. H., “Motor Transportation for Rural Districts,” Bulletin 770 of the United States Department of Agriculture.

Cowan, D. R. and Hart, F. C., “Motor Transportation in Rural Ontario,” Bulletin 227, Ontario Department of Agriculture, 1920.

Dana, Richard T., “Hand Book of Construction Equipment,” pp. 550-559, 767-772.

Firestone Ship by Truck Bureau, Akron:

Bulletin No. 1, “Ship by Truck among Farmers through Coöperative Associations”; Bulletin No. 2, “How and Where to Establish Truck Routes”; Bulletin No. 3, “The Motor Truck at the Coal Mines”; Bulletin No. 4, “The Farmer and the Motor Truck”; Bulletin No. 5, “Costs and Their Relation to Truck Transportation.”

Highway and Highway Transport Education Committee.—“Proceedings of a Conference on the Economics of Highway Transport, Held at the University of Maryland, July 27, 1921,” Washington, D. C.

Kentucky, University of, College of Agriculture Circular No. 130, “Marketing Farm Products.” Lexington, Ky., June, 1922.

Lane, F. Van Zant, “Motor Truck Transportation,” D. Van Nostrand Company, New York.

National Automobile Chamber of Commerce, New York:

“Facts and Figures of the Automobile Industry, 1921.”