Held, Gilbert,  1943- <br/><br/>
Understanding data communications / 
Gilbert Held. 
 - 7th ed. 
 - Boston :  Addison-Wesley,  c2002. 
 - xv, 765 p. :  ill. ;  23 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>0672322161 9780672322167 
<br/><br/><label>LCCN: </label>2001089583 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems.<br/>Computer networks.
<br/><br/><label>LC Class. No.: </label>TK5105  / H429 2002 
<br/><br/><label>Dewey Class. No.: </label>004.6 H.G.U 2002