00277nam a2200109Ia 4500082002000000100002100020245003900041260004800080300002900128500000500157700000500162  a515.73bP885.AT  aPowell, M. J. D.  aApproximation theory and methodsb  aCambridgebCambridge University Pressc1981  ax, 339p. Index. Appendix  a  a