Held, Gilbert  <br/><br/>
Understanding data communications 
Gilbert Held 
 - 7th ed. 
 - Delhi  Pearson Education (Singapore)  2002 
 - xv, 765p.  
<br/><br/><label>ISBN: </label>9788129702111 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems<br/>Computer networks
<br/><br/><label>Dewey Class. No.: </label>004.6  / H366u7