Harper, Robert, <br/><br/>
Between two worlds :  An introduction to geography 2nd ed / 
Robert Harper. 
 - Second edition. 
 - United States :  Houghton Mifflin Company,  1978. 
 -  v, 597 pages : 
<br/><br/><label>ISBN: </label>0395251648 
<br/><br/><label>Dewey Class. No.: </label>910   / H11