Gaddum, Leonard W.  <br/><br/>
Our physical environment :   a problem approach / 
Leonard W. Gaddum and Harold L. Knowles. 
 - New York ;  Houghton Mifflin,  c 1953. 
 - x, 625 p. :  ill. ;  24 cm. 
<br/><br/> Includes index. 
<br/><br/>332  332 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology.
<br/><br/><label>Dewey Class. No.: </label>551 / G547o