@article{IVM_1989_5_a13,
     author = {V. A. Derkach and M. M. Malamud},
     title = {A class of extensions of {a~Hermitian} operator and the {Weyl} function},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {71--75},
     publisher = {mathdoc},
     number = {5},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1989_5_a13/}
}