Held, Gilbert <br/><br/>
Understanding data communications / 
Gilbert Held 
 - New delhi:  Pearson education,  2011 
 - 766 p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer science
<br/><br/><label>Dewey Class. No.: </label>4.6  / HEL/U