American commodity flow : a geographical interpretation of rail and water traffic based on principles of spatial interchange /
Ullman, Edward Louis, 1912-1976
American commodity flow : a geographical interpretation of rail and water traffic based on principles of spatial interchange / by Edward L. Ullman - Seattle : University of Washington Press, 1957 - xxii, 214 p. : ill., maps ; 23 cm.
Includes bibliographical references (p. 207-213) and index
Transportation--United States
United States--Commerce
American commodity flow : a geographical interpretation of rail and water traffic based on principles of spatial interchange / by Edward L. Ullman - Seattle : University of Washington Press, 1957 - xxii, 214 p. : ill., maps ; 23 cm.
Includes bibliographical references (p. 207-213) and index
Transportation--United States
United States--Commerce
