@article{KUTGS_1984_16_a6,
     author = {V. G. Kopp},
     title = {Invariant groups of motions in a {Euclidean} space $R_4$},
     journal = {Trudy Geometricheskogo Seminara},
     pages = {47--64},
     publisher = {mathdoc},
     volume = {16},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUTGS_1984_16_a6/}
}