Helfert E A <br/><br/>
Techniques of ficial analysis 
Helfert E A 
 - 9 
 - New Delhi  New Delhi, McGraw Hill  2004 
 - xix,457 
<br/><br/><label>ISBN: </label>0-07-059041-9 
<br/><br/><label>Source: </label>Textbook