@article{DAN_1967_172_1_a9,
     author = {K. S. Sibirskii},
     title = {Unitary and orthogonal invariants of matrices},
     journal = {Doklady Akademii Nauk},
     pages = {40--43},
     year = {1967},
     volume = {172},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_172_1_a9/}
}