@article{AA_1991_3_3_a3,
     author = {A. L. Koldobskii},
     title = {The {Schoenberg} problem on positive-definite functions},
     journal = {Algebra i analiz},
     pages = {78--85},
     publisher = {mathdoc},
     volume = {3},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_1991_3_3_a3/}
}