@article{VNGU_2011_11_4_a1,
     author = {A. V. Belykh and A. V. Greshnov},
     title = {$cc${-Homogeneous} {Cone} {Condition} and $cc${-Balls} on {Heizenberg} {Groups}},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {8--20},
     publisher = {mathdoc},
     volume = {11},
     number = {4},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2011_11_4_a1/}
}