Gamma, Erich Helm, Richard <br/><br/>
Design Patterns: Elements of Reusable Object- Oriented Software  

 - New Delhi  Pearson  2009 
 - p.395 
<br/><br/><label>ISBN: </label>0201455633 
<br/><br/><label>Dewey Class. No.: </label>621.381958 G193