1. Basic convergence with rates of smooth Picard singular operators;Anastassiou;J. Comput. Anal. Appl.,2006
2. Remark on the degree of approximation of continuous functions by singular integrals;Gal;Math. Nachr.,1993
3. Degree of approximation of continuous functions by some singular integrals;Gal;Rev. Anal. Numér, Théor. Approx. (Cluj),1998
4. On the rate of convergence of singular integrals for Hölder continuous functions;Mohapatra;Math. Nachr.,1990
5. Moments in Probability and Approximation Theory;Anastassiou,1993