Telecom report :   multiplexing & line transmission /  
Siemens. 
 - 1a. ed. 
 - [S. L.] :  Siemens,  1987 
 - 346 p. :    ilus. ; lám. col. ;    30 cm 
<br/><br/><label>LC Class. No.: </label> / S 38 
<br/><br/><label>Universal Decimal Class. No.: </label>654.93