@article{SM_1975_27_4_a4,
     author = {A. F. Nikiforov and V. B. Uvarov},
     title = {On~a~new approach to the theory of special functions},
     journal = {Sbornik. Mathematics},
     pages = {515--525},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1975},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1975_27_4_a4/}
}