@article{IVM_1960_6_a15,
     author = {A. E. Liber},
     title = {Differential comitants of various linear objects},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {158--162},
     year = {1960},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1960_6_a15/}
}