@article{DAN_1969_186_6_a3,
     author = {M. M. Gekhtman},
     title = {On the question of the spectrum of selfadjoint extensions of a symmetric semibounded operator},
     journal = {Doklady Akademii Nauk},
     pages = {1250--1252},
     publisher = {mathdoc},
     volume = {186},
     number = {6},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_186_6_a3/}
}