Gary B. Shelly, <br/><br/>
Business data communications :  introductory concepts and techniques / 
by Gary B. Shelly, Thomas J. Cashman, Judy A. Serwatka 
 - Fourth edition 
 - xv, [500] pages :  some colour, illustrations ;  28 cm 
 - Sherly Cashman Series .
<br/><br/>Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>9780789568069 (paperback) 0789568063 (paperback) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data transmission systems
<br/><br/><label>LC Class. No.: </label>HD30.335   / S54