1. On the degree of approximation of smooth functions by linear saturated operators;Baskakov;East J. Approx.,1995
2. Fourier Analysis and Approximation, I;Butzer,1971
3. Introduction to the Theory of Uniform Approximation of Functions by Polynomials;Dzjadyk,1977
4. Lectures on Complex Approximation;Gaier,1987
5. On Faber polynomials and Faber expansions;Kövari;Math. Z.,1967