@article{DAN_1958_118_5_a0,
     author = {B. M. Bredikhin},
     title = {Free numerical semigroups with power densities},
     journal = {Doklady Akademii Nauk},
     pages = {855--857},
     publisher = {mathdoc},
     volume = {118},
     number = {5},
     year = {1958},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_118_5_a0/}
}