Data and computer communications/  English 
William Stallings 
 - 7th Ed. 
 - New Delhi:  Asoke K. Ghosh,  2004. 
 - xv, 847p.:  maps,:  23.5cm. 
<br/><br/><label>ISBN: </label>8120323556 
<br/><br/><label>Dewey Class. No.: </label>681.14:65.012.45  / STA