Advances in agronomy  
/ Academic Press  
 - New York:   Academic Press,   1969 
 - 340p.  
<br/><br/> Vol. 21 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science 
<br/><br/><label>Subjects--Index Terms: </label>Agronomy  
<br/><br/><label>Universal Decimal Class. No.: </label>631(05)