@article{IVM_1975_7_a16,
     author = {B. P. Chebysheva},
     title = {Framing a~hypersurface in a~space with degenerate metric},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {117--120},
     year = {1975},
     number = {7},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1975_7_a16/}
}