Tripp, Robert. <br/><br/>
Planned change in farming systaems :  progress in on-farm research 
/ed. by Robert Tripp 
 - Chichester, England :  Wiley & Sons,  1991. 
 - 348 p. : 
<br/><br/> gráfs. ; mapas ; tablas ; diags. 
<br/><br/><label>ISBN: </label>0 471 934178 
<br/><br/><label>LCCN: </label>78091 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agricultura--Investigación.<br/>Política agrícola.
<br/><br/><label>Dewey Class. No.: </label>338.9  / T72