Protection of water resoruces , water quality and 

 - New York  United Nations U S A       1995 
 - 317p.  cm. 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Engneering
<br/><br/><label>Dewey Class. No.: </label>X9(D24).4.N9, N5