Conservation in the United States / 
A. F. Gustafson [...et. al.] 
 - 3rd ed. 
 - Ithaca, N. Y. :  Comstock Pub. Co.,  1949. 
 - ix, 534 p. :  illus. ;  24 cm. 
<br/><br/> Includes index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural resources--United States.<br/>Conservation of natural resources--United States.<br/>Soil conservation--United States.
<br/><br/><label>Subjects--Geographic Terms: </label><br/>United States--Economic conditions.
<br/><br/><label>Dewey Class. No.: </label>333.72  / CON 1949