TY  - BOOK
AU  - Perle,Eugene D.
TI  - The demand for transportation: regional and commodity studies in the United States 
PY  - 1964///
CY  - Chicago
PB  - Dept. of Geography, University of Chicago
KW  - Freight and freightage
KW  - United States
KW  - Mathematical models
N1  - Bibliography : p. 127-130
ER  -