TY  - BOOK
AU  - Hopkins, Donald P.
TI  - Chemicals, humus and the soil; a simple presentation of contemporary knowledge and opinions about fertilizers, manures and soil fertility
U1  - 631.8 
PY  - 1945///
CY  - London
PB  - Faber and Faber
KW  - Fertilizantes y abonos
KW  - Humus
ER  -