Williams, Moyle S.  1921- <br/><br/>
Crop production levels and fertilizer use / 
by Moyle S. Williams and John W. Couston 
 - Rome :  Food and Agriculture Organization of the United Nations,  1962 
 - 48 p. :  ill. ;  23 cm. 
<br/><br/>Includes bibliography 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fertilizers<br/>Crop yields<br/>Fertilizers--Economic aspects<br/>Fertilizers--Developing countries