Global Approximation Theorems for Szaisz-Mirakjan and Baskakov Operators in Polynomial Weight Spaces Michael Becker Indiana University Mathematics Journal 1978 text pdf 10.1512/iumj.1978.27.27011 10.1512/iumj.1978.27.27011 en Indiana Univ. Math. J. 27 (1978) 127 - 142 state-of-the-art mathematics http://iumj.org/access/