TY  - GEN
AU  - Pararajasinham , E.
AU  - Bandara , Nilanthi 
AU  - Mendis , D.L.O.
TI  - Technology society and environment block 3
U1  - 333 
PY  - 1990///
CY  - Nugegoda
PB  - Open University
KW  - ECONOMICS
ER  -