@article{FAA_1977_11_2_a5,
     author = {M. A. Rvachev},
     title = {A problem of {Ulam} type},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {58--66},
     publisher = {mathdoc},
     volume = {11},
     number = {2},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1977_11_2_a5/}
}