GRAY N.F. <br/><br/>
Activated Sludge : Theory and Practice 

 -  1990  Oxford University Press 
 - 1-272  0  Paper 
<br/><br/> Hard Binding 
<br/><br/><label>ISBN: </label>0-19-856341-8 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Soil & Water Conservation
<br/><br/><label>Dewey Class. No.: </label>DT555         N0