@article{IVM_1982_12_a12,
     author = {V. L. Kreptogorskii},
     title = {Two-dimensional $K$-families},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {67--70},
     year = {1982},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1982_12_a12/}
}