00285nam a2200121Ia 4500008004100000041001200041082001600053100001500069245002900084260003400113300000800147650000800155221030s9999    xx            000 0 und d  aEnglish  a105.23bLan  aG. Langley 0aTelecommunication Primer  bGalgotia PubaNew Delhic1986  a148  aECE