TY  - BOOK
AU  - Billings W D
TI  - Plants and the ecosystem
T2  - Foundamentals of botany series
U1  - I:5, K4;2   TI 
PY  - 1964///
CY  - London
PB  - Macmillan         
KW  -  Plant ecology
KW  - Botany
ER  -