TY  - BOOK
AU  - Singh,H.S.
TI  - Principles of environmental conservation
SN  - 8170891019
U1  - 363.7 22
PY  - 1989///
CY  - Dehra Dun
PB  - international book distributors
KW  - ecosystem
KW  - Environmental protection
N1  - Includes bibliographical references and index
ER  -