Conservation in the United States / 
A. F. Gustafson ...[et al.]. 
 - 3rd ed. 
 - New York :  Comstock,  c 1949. 
 - ix, 534 p. :  ill. ;  24 cm. 
<br/><br/> Includes index. 
<br/><br/>337  337 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>United States--Economic conditions.<br/>United States--Natural resources.
<br/><br/><label>Dewey Class. No.: </label>333.7273 / G978c