00297nam a2200121Ia 4500082002100000100001600021245004800037260002700085300002000112490003300132500000500165700000500170  a515.55bAl384.CP  aAlexits, G.  aConvergence problems of orthogonal seriesb  aOxfordbPergamonc1961  aix, 350p. Index  aPure and Applied Mathematics  a  a