TY  - BOOK
AU  - Powers,Laura E.
AU  - McSorley,Robert
TI  - Ecological principles of agriculture
SN  - 0766806537
AV  - S589.7 .P68 2000
U1  - 630.277 
PY  - 2000///
CY  - New York
PB  - Delmar
KW  - Agricultural ecology
ER  -