@article{BUMI_1959_3_14_1_a13,
     author = {Popov, Blagoj S.},
     title = {On ultraspherical polynomials.},
     journal = {Bollettino della Unione matematica italiana},
     pages = {105--108},
     publisher = {mathdoc},
     volume = {Ser. 3, 14},
     number = {1},
     year = {1959},
     zbl = {0085.06101},
     mrnumber = {106300},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BUMI_1959_3_14_1_a13/}
}