Gonzales, Gaudiosa A.; Aguilar, Riza O.  c2001 <br/><br/>
Aquatic Ecosystems 
Gonzales, Gaudiosa A.; Aguilar, Riza O. 
 - Diliman, Quezon City, Philippines  UP Open University  c2001 
 - viii., 438p.  ill.,  12 inch.