Cannon, Don L. <br/><br/>
Understanding communications systems / 
written by Don L. Cannon, Gerald Luecke ; with contributions by Charles W. Battle [et al.]. 
 - 2st. ed., 4th printing. 
 - Indianapolis :  Howard W. Sams & Co.,  cop. 1984. 
 - IV, 284 s. :  wykr., fot., rys., tabl. ;  23 cm. 
 - Sams Understanding Series .
 - Sams Understanding Series .
<br/><br/><label>ISBN: </label>0672270161 
<br/><br/><label>Universal Decimal Class. No.: </label>621.39