@article{VMUMM_1999_2_a2,
     author = {A. E. Pankratiev},
     title = {Hyperbolic products of groups},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {9--13},
     publisher = {mathdoc},
     number = {2},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1999_2_a2/}
}