TY  - BOOK
AU  - Ruthenberg, Hans.
TI  - Farming systems in the tropics
T2  - Oxford science publications
U1  - 631.0913 
PY  - 1980///
CY  - Oxford
PB  - Clarendon
KW  - Agricultura
KW  - Trópicos
KW  - Sistemas de cultivo
ER  -