00370nam a2200097Ia 4500008004100000082002200041100001800063245013200081260004300213300001600256251203b        |||||||| |||| 00| 0 eng d  a382.0973bUl42.AC  aUllman, E. L.  aAmerican commodity flowb: a geographical interpretation of rail and water traffic based on principles of spatial interchange /  aSeattle:bWashington University,c1957  axxii, 215p.