00246nam a2200097Ia 450000500170000000800410001710000180005824500280007626000360010430000080014020260413100419.0230516s9999||||xx |||||||||||||| ||und||  aDogra, Rakesh 0aEssentials of  p hysics  bDelhi  ,s.k. Katria &Sonsc1997  a325