@article{DAN_1987_295_3_a4,
     author = {S. N. Naboko},
     title = {On the structure of roots of operator-valued functions with positive imaginary part in the classes $\sigma_p$},
     journal = {Doklady Akademii Nauk},
     pages = {538--541},
     publisher = {mathdoc},
     volume = {295},
     number = {3},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_295_3_a4/}
}