TY  - BOOK
AU  - Toews,  Waltner - David
TI  - Ecosystem sustainability and health:   a practical Approach 
SN  - 9780521531856
AV  - QH 75 .W35 
PY  - 2004///
CY  - Cambridge
PB  -  Cambridge University Press
KW  - Ecosystem Management
ER  -