Thornbury, Willaim D., <br/><br/>
Principlesof geomorphology 
by William D. Thornbury 
 - 2nd ed. /  
 - Vija  CBS Publishers & Dishtributors  2004 
 - xi, 594p. 
<br/><br/><label>Source: </label> Geography 
<br/><br/><label>Dewey Class. No.: </label>U21  / P4