@article{DAN_1961_138_3_a23,
     author = {L. N. Gutman and L. N. {\CYRM}{\cyra}l'{\cyrk}{\cyro}},
     title = {On theory of fronts},
     journal = {Doklady Akademii Nauk},
     pages = {587--590},
     publisher = {mathdoc},
     volume = {138},
     number = {3},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_138_3_a23/}
}