@article{DAN_1992_322_2_a4,
     author = {V. M. Miklyukov},
     title = {On a {Lorentz-invariant} characteristic of maximal tubes in the},
     journal = {Doklady Akademii Nauk},
     pages = {233--236},
     publisher = {mathdoc},
     volume = {322},
     number = {2},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_322_2_a4/}
}