Perle, Eugene D. <br/><br/>
The demand for transportation :  regional and commodity studies in the United States / 
by Eugene D. Perle 
 - Chicago :  Dept. of Geography, University of Chicago,  1964 
 - xx, 130 p. :  maps ;  23 cm. 
 - Research paper (University of Chicago. Dept. of Geography) ;  no.95 .
<br/><br/>Bibliography : p. 127-130 
<br/><br/><label>LCCN: </label>64-023589 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Freight and freightage--Mathematical models--United States