TY  - BOOK
AU  - Hellawell, J.M.
AU  - 
TI  - Biological Indicaors of Freshwater Pollution and Environmental Management
U1  - 629.19 
PY  - 1986///
CY  - London
PB  - Elsevier Applied Science
KW  - Water Pollution and Environmental Management
N1  -  Bibliog p. 452 -508
ER  -