@article{VMUMM_2006_6_a11,
     author = {A. V. Petrikov},
     title = {On orbits of points on the {Lobachevskii} plane under the action of integer matrices},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {50--53},
     publisher = {mathdoc},
     number = {6},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2006_6_a11/}
}