TY  - BOOK
AU  - Tompkins,Peter
AU  - Bird,Christopher
TI  - Secrets of the soil
SN  - 0670835617 
PY  - 1991///
CY  - London
PB  - Viking Arkana
KW  - Soils
KW  - Soil management
KW  - Organic farming
KW  - Agricultural ecology
ER  -