Electronic communications 
Roddy, Dennis,. 
 - 4th ed. 
 -  Prentice Hall Career and Technology,  1995 
 - ix, 820 p. 
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<br/><br/><label>Subjects--Topical Terms: </label><br/>Telecommunication.
<br/><br/><label>Dewey Class. No.: </label>621.381 R61e 1995