@article{IVM_1993_8_a1,
     author = {A. B. Kotlyar},
     title = {On an upper bound on extrinsic curvatures for some classes of multidimensional surfaces in an $n$-dimensional {Lobachevskii} space},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {9--18},
     year = {1993},
     number = {8},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1993_8_a1/}
}