Inequalities of Calderón-Zygmund type for trigonometric polynomials. Runovski, K.; Schmeisser, H.-J. — 2001 Georgian Mathematical Journal
On the method of approximation by families of linear polynomial operators. Burinska, Z.; Runovski, K.; Schmeisser, H.-J. — 2000 Zeitschrift für Analysis und ihre Anwendungen