@article{GDZPPN002347288, title = {Mean Summability for Ultraspherical Polynomials.}, journal = {Mathematica Scandinavica}, volume = {13}, year = {1963}, pages = {167-177}, zbl = {0132.29501}, url = {http://dml.mathdoc.fr/item/GDZPPN002347288} }
Askey, Richard; Hirschman, I.I. Jr. Mean Summability for Ultraspherical Polynomials.. Mathematica Scandinavica, Tome 13 (1963) pp. 167-177. http://gdmltest.u-ga.fr/item/GDZPPN002347288/