Held, Gilbert. <br/><br/>
Data communications networking devices : characteristics, operation, applications  [Books]. 
Gilbert Held 
 - 2nd.ed. 
 - New York  John Wiley & Sons  1989 
 - Pages: 493. 
<br/><br/><label>ISBN: </label>0471918695  0.00 
<br/><br/><label>Subjects--Personal Names: </label><br/>Computer networks.<br/>Data transmission systems.
<br/><br/><label>Dewey Class. No.: </label>TK/5105.5  / HEL