Armstrong G <br/><br/>
Principles of marketing 
Armstrong G; Kotler P 
 - New Delhi  New Delhi, Prentice-Hall of India pvt. ltd.  1999 
 - 635+118. 
<br/><br/><label>ISBN: </label>81-203-1490-5 
<br/><br/><label>Source: </label>Textbook