Introducing Computarised Telephone Switchboards [PABxs] 

 - 1a impr 
 - Manchester :   The National Computing Centre Limited N.C.C.,   1982. 
 - 92 p. : 21 cm. 
<br/><br/><label>ISBN: </label>085012364X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>ESTACIONES TELEFONICAS
<br/><br/><label>Universal Decimal Class. No.: </label>621.395.7