@article{IVM_1984_11_a14,
     author = {V. V. Shurygin},
     title = {On the theory of higher-order differential groups},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {77--81},
     year = {1984},
     number = {11},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1984_11_a14/}
}