TY - JOUR AU - Szal, Bogdan TI - Trigonometric approximation by Nörlund type means in $L^p$-norm JO - Commentationes Mathematicae Universitatis Carolinae PY - 2009 SP - 575 EP - 589 VL - 50 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/CMUC_2009__50_4_a7/ LA - en ID - CMUC_2009__50_4_a7 ER -