@article{KYB_1981__17_5_a6,
     author = {Konstantinov, M. M. and Petkov, P. Hr. and Christov, N. D.},
     title = {Invariants and canonical forms for linear multivariable systems under the action of orthogonal transformation groups},
     journal = {Kybernetika},
     pages = {413--424},
     publisher = {mathdoc},
     volume = {17},
     number = {5},
     year = {1981},
     mrnumber = {648213},
     zbl = {0474.93020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1981__17_5_a6/}
}