00300nam a2200121Ia 45000030006000000080041000060400015000471000016000622450049000782600022001275460012001490050017001610STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aAyres Frank  aTheory and problems of differntial equations  bMcgraw hillc1952  aEnglish20220125165947.0