Álvarez Febles, Nelson, <br/><br/>
La tierra viva  manual de agricultura ecológica 
Nelson Alvarez Febles. 
 - Ed. 2010. 
 - Universidad Metropolitana, P.R.  Nomos  2010. 
 - 282 p.  ill.  26 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>0963342932 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Agricultural ecology<br/>Ecology<br/>Agriculture -- Environmental aspects -- Ecology.