Held, Gilbert,  1943- <br/><br/>
Understanding data communications / 
Gilbert Held. 
 - 7th ed. 
 - New Delhi :  Pearson Education,  c2002. 
 - xv, 765 p. :  ill. ;  23 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>8131708721 (alk. paper) 
<br/><br/><label>LCCN: </label>2001089583 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer networks.<br/>Data transmission systems.
<br/><br/><label>LC Class. No.: </label>TK5105  / H429 2002 
<br/><br/><label>Dewey Class. No.: </label>004.6  / HEL