Hughes, Harold D. ,  1882 <br/><br/>
Crop production / 
by Harold D. Hughes and Darrel S. Metcalfe 
 - 3rd ed. 
 - New York :  MacMillan,  1972 
 - xi, 627 p. :  ill. ;  24 cm. 
<br/><br/>Includes bibliographies 
<br/><br/><label>LCCN: </label>75-146619 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Field crops