Basic technics in ecological farming :  papers presented at the 2nd international conference held by the IFOAM, Montreal, October 1-5, 1978 ; The Maintenance of soil fertility : exposés présentés à la 3 ème conférence internationale organisée par IFOAM, Bruxelles, du 3 au 5 Septembre 1980 / 
edited by Stuart Hill, Pierre Ott. 
 - Basel, Switzerland :  Birkhäuser Verlag,  1982 
<br/><br/> English and French 
<br/><br/>Includes bibliographies 
<br/><br/><label>ISBN: </label>3764313749 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Organic farming--Congresses<br/>Agricultural ecology--Congresses<br/>Agriculture--Congresses<br/>Soil fertility--Congresses