TY  - SER
AU  - Vlek, P. L. G.,
TI  - Fertilizer Research Vol. 29(1-3), Vol. 30 (1-3)
U1  - 631 
PY  - 1991///
CY  - Dordrecht
PB  - Kluwer Academic Publishers
KW  - Fertilizers
KW  - Techniques, equipment & materials
ER  -