@article{MZM_1980_28_6_a3,
     author = {L. I. Vainerman},
     title = {Extensions of closed operators in {Hilbert} space},
     journal = {Matemati\v{c}eskie zametki},
     pages = {833--842},
     publisher = {mathdoc},
     volume = {28},
     number = {6},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1980_28_6_a3/}
}