AU  - Costa, H.H.
TI  - Freshwater as a natural resource in  sri Lanka
T2  - Science Education Series
CY  - NARESA
PB  - Colombo
KW  - Education
KW  - Aquatic Resources
N1  - http://thakshana.nsf.ac.lk/slstic/NA-111/NA_111.pdf
ER  -