Approximation theorems for functions of Hölder classes M. Górzeńska; M. Leśniewicz; L. Rempulska — 1991 Commentationes Mathematicae The article contains no abstract
On the limit properties of the Picard singular integral. Górzeńska, M.; Rempulska, L. — 1994 Publications de l'Institut Mathématique. Nouvelle Série