00273nam a2200121Ia 4500008004100000041001200041082001600053100002100069245002100090260002500111300000800136650000700144221030s9999    xx            000 0 und d  aEnglish  a105.23bVal  aM. V. Valkenburg 0aNetwork Analysis  bPHIaNew Delhic1997  a571  aEE