@article{IVM_2003_11_a0,
     author = {M. A. Akivis and V. V. Goldberg},
     title = {Varieties with a degenerate {Gauss} mapping with multiple foci, and twisted cones},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {3--14},
     publisher = {mathdoc},
     number = {11},
     year = {2003},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2003_11_a0/}
}