TY  - BOOK
AU  - Edwards, Clive Arthur
TI  - Sustainable agricultural systems
U1  - 338.162 
PY  - 1990///
CY  - Ankeny, Iowa
PB  - Soil and Water Conservation Society
KW  - Agricultura sustentable
KW  - EcologÃ­a agrÃ­cola
KW  - PolÃ­tica agrÃ­cola
KW  - Sistemas de cultivo
N1  - 64-102
ER  -