Fitzgerald, Jerry.  <br/><br/>
Business data communications : basic concepts,security, and design,3rd ed. / Jerry fitzgerald.  

 - New York : Wiley, c1990.  
<br/><br/><label>ISBN: </label>0471517836 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Data transmission systems. 
<br/><br/><label>Dewey Class. No.: </label>004.6 FIR