00275nam a2200121Ia 45000030006000000080041000060400015000471000018000622450035000802600009001155460012001240050017001360STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aBaum John, D.  aElements of point set topology  c1964  aEnglish20220125165939.0