@article{IVM_1960_4_a16,
     author = {A. Z. Petrov and V. R. Kaigorodov and V. N. Abdullin},
     title = {Classification of gravitational fields of general type by the group of motions. {I,} {II,} {III}},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {158--169},
     publisher = {mathdoc},
     number = {4},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1960_4_a16/}
}