TY  - BOOK
AU  - Singh,H.S..
TI  - Principles of environmental conservation / 
SN  - 8770891019
U1  - 577 
PY  - 1989///
CY  - Dehradun : 
PB  - International Book Distributors , 
KW  - CONSERVATION OF NATURAL RESOURCES
N1  - Includes bibliographical referenes
ER  -