00389nam a2200121 a 450000500170000002000150001708200150003210000210004724500700006826000480013830000250018649000560021120251203110904.0  a0821830201  a510.8bNIK  aNikol'skii, K.N.  aSelected problems of weighted approximation and spectral analysis  aIslandbAmerican Mathematical Societyc1976  aiv,276p.c26 cm.bPB  aProceedings of the steklov institute of mathematics