@article{MZM_1978_24_2_a11,
     author = {N. N. Frolov},
     title = {Essential self-adjointness of an infinite-dimensional operator},
     journal = {Matemati\v{c}eskie zametki},
     pages = {241--248},
     publisher = {mathdoc},
     volume = {24},
     number = {2},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1978_24_2_a11/}
}