TY - JOUR AU - S. S. Shterengas TI - Riesz-summation of fourier series with respect to the eigenfunctions of an abstract operator JO - Matematičeskie zametki PY - 1979 SP - 865 EP - 873 VL - 26 IS - 6 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MZM_1979_26_6_a5/ LA - ru ID - MZM_1979_26_6_a5 ER -