%A Runck Paul Otto %A Szabados JĂłzsef %A VĂŠrtesi PĂŠter %N 3-4 %P 287-293 %D 1989 %L acta15236 %O Bibliogr.: 293. p. %K Matematika %T On the convergence of the differentiated trigonometric projection operators %J Acta scientiarum mathematicarum %V 53