@article{UZERU_1987_2_a0,
     author = {G. V. Virabyan},
     title = {On some general properties of metrical operators generated by quadratic operator pencils},
     journal = {Proceedings of the Yerevan State University. Physical and mathematical sciences},
     pages = {3--8},
     publisher = {mathdoc},
     number = {2},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZERU_1987_2_a0/}
}