@article{TMF_1983_57_1_a14,
     author = {L. D. Pustyl'nikov},
     title = {On {Ulam's} problem},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {128--132},
     publisher = {mathdoc},
     volume = {57},
     number = {1},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1983_57_1_a14/}
}