00311nam a2200121Ia 45000030006000000080041000060400015000471000018000622450071000802600009001515460012001600050017001720STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aYoung, J.W.A.  aTeaching of mathematics in the elementary and the secondary school  c1919  aEnglish20220125170024.0