Oelhaf, Robert C. <br/><br/>
Organic agriculture ; economic and ecological comparisons with conventional methods 

 - New York :  Allanheld,  1978 
 - 271 p. 
<br/><br/><label>LCCN: </label>34036 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Abonos.<br/>Control biológico de plagas.<br/>Medio ambiente--Contaminación.<br/>Sistemas de cultivo.
<br/><br/><label>Dewey Class. No.: </label>631.5  / O4