00281nam a2200121Ia 45000030006000000080041000060400015000471000016000622450025000782600027001035460012001300050017001420STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aGupta, B.D.  aMathematical physics  bVani Educationalc1978  aEnglish20220125170026.0