TY  - BOOK
AU  - Downing,John A  .
AU  - Rigler,Frank H  .
TI  - A manual on methods for the assessment of secondary productivity in fresh waters / 
SN  - 0632006161
U1  - 553.7 
PY  - 1984///
CY  - London : 
PB  - Blackwell Scientific Publns. , 
KW  - FRESHWATER PRODUCTIVITY
N1  - Includes bibliographical references and index
ER  -