TY  - GEN
AU  - Hatfied , J.L
AU  - Karlen , D.L
TI  - Sustainable agriculture systems
SN  - 1566700493
U1  - 630 
PY  - 1993///
CY  - New Delhi
PB  - LEWIS Publihers
KW  - Agriculture
KW  - Sustainable Agriculture
ER  -