Operation and maintainence of urban water supply and sanitation systems:   A guide for managers  
/ WHO 
 - Geneva:   WHO,   1994 
 - ix, 102p. 
<br/><br/><label>ISBN: </label>9241544716 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science
<br/><br/><label>Universal Decimal Class. No.: </label>628.1(1-21)   / N4