J.A nicholas wallis <br/><br/>
Intensified systems of farming in the topics and subtopics 

 -  The world bank N.Y washington  1997 
 - 220 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agriculture
<br/><br/><label>Dewey Class. No.: </label>630.913  / WAL