@article{IVM_1968_1_a10,
     author = {L. N. Krivonosov},
     title = {Principal nets of parallel and normal correspondence of surfaces in $E_4$},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {81--91},
     publisher = {mathdoc},
     number = {1},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1968_1_a10/}
}