00335nam a2200121Ia 4500082002100000100001700021245006300038260002900101300001400130490005900144500000500203700000500208  a515.73bSi617.TB  aSinger, Ivan  aThe theory of best approximation and functional analysisb  aPennsylvaniabSIAMc1974  avii, 95p.  aRegional conference series in Applied Mathematicsv 13  a  a