TY  - GEN
AU  - Arudpragasam , K.D. 
AU  - Balasooriya , I.
AU  - Gunawrdena , N.J.
TI  - Environmental studies part I the natural environment : level 3. BTU 1120
U1  - 333.7 
CY  - Nugegoda
PB  - The Open University
KW  - Natural Resources
KW  - Environmental Studies
KW  - Environmental Sciences
ER  -