Duggal, K.N. <br/><br/>
Elements of environmental engineering 
by K.N. Duggal 
 - 1st rev. ed. 
 - New Delhi:  S. Chand & Company Ltd.  2007 
 - xvii, 440p. 
<br/><br/><label>ISBN: </label>9788121915472 
<br/><br/><label>Dewey Class. No.: </label>D0aG:55  / P7