@article{KUTGS_1991_21_a14,
     author = {A. P. Shirokov},
     title = {On the geometry of horospheres of the {Lobachevskii} space},
     journal = {Trudy Geometricheskogo Seminara},
     pages = {118--124},
     publisher = {mathdoc},
     volume = {21},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUTGS_1991_21_a14/}
}