@article{UZKU_1965_125_1_a6,
     author = {V. G. Kopp},
     title = {Infinitesimal motions of a four-dimensional {pseudoEuclidean} space of zero-signature},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {100--107},
     publisher = {mathdoc},
     volume = {125},
     number = {1},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_1965_125_1_a6/}
}