@article{DAN_1983_272_2_a3,
     author = {A. S. Bratus' and A. P. Seyranian},
     title = {Double eigenvalues in optimization problems},
     journal = {Doklady Akademii Nauk},
     pages = {275--278},
     year = {1983},
     volume = {272},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_272_2_a3/}
}