@article{MZM_2014_95_1_a13,
     author = {A. V. Ustinov},
     title = {On the {Three-Dimensional} {Vahlen} {Theorem}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {154--156},
     publisher = {mathdoc},
     volume = {95},
     number = {1},
     year = {2014},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2014_95_1_a13/}
}