@article{MZM_1988_44_4_a12,
     author = {P. M. Tishin},
     title = {Criterion for the stability of the partial indices of a circular matrix function},
     journal = {Matemati\v{c}eskie zametki},
     pages = {536--545},
     publisher = {mathdoc},
     volume = {44},
     number = {4},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1988_44_4_a12/}
}