00328nam a2200133Ia 4500008004100000020001500041041001200056082001600068100001600084245004100100260003200141300000900173650001200182221030s9999    xx            000 0 und d  a0706996836  aEnglish  a105.23bGup  aB. D. Gupta 0aMathematical Physicscby B. D. Gupta  bVikas Pub.aNew Delhic1999  a7.65  aPhysics