%0 Journal Article %A I. I. Sharapudinov %T Some special series in ultraspherical polynomials and their approximation properties %J Izvestiya. Mathematics %D 2014 %P 1036-1059 %V 78 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM2_2014_78_5_a8/ %G en %F IM2_2014_78_5_a8