00339nam a2200133Ia 45000030006000000080041000060400015000471000030000622450054000922500010001462600020001565460012001760050017001880STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aSudhin, K.; Mukho Padhyay  aSources of variation in agricultural productivity  aFirst  bMacmillanc1976  aEnglish20220125165552.0