Held , Gilbert  . <br/><br/>
Understanding Data Communications /   Textual Documents 
Gilbert Held. 
 - 4 /   . 
 - New Delhi :   Prentice Hall of India ,   1994. 
 - NULL ;   NULL. 
<br/><br/><label>Subjects--Index Terms: </label>Data Communication 
<br/><br/><label>Dewey Class. No.: </label>005.71  / HEL;1