An extension to rational functions of a theorem of J. L. Walsh on differences of interpolating polynomials E. B. Saff; A. Sharma; R. S. Varga — 1981 ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique
Converse results in the Walsh theory of overconvergence A. S. Cavaretta; A. Jr. Sharma; R. S. Varga — 1985 ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique