Stallings, William <br/><br/>
Network security essentials 
by William Stallings 
 - 4th ed.  
 - Boston   Pearson Education  2011 
 - 431 pages; 23 cm. 
<br/><br/> includes index  
<br/><br/><label>ISBN: </label>978-0-13-706792-3 
<br/><br/><label>Dewey Class. No.: </label>005.8/St1/2011