@article{SM_1974_22_2_a0,
     author = {Yu. L. Shmul'yan},
     title = {On closed {Hermitian} operators and their selfadjoint extensions},
     journal = {Sbornik. Mathematics},
     pages = {151--166},
     year = {1974},
     volume = {22},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_22_2_a0/}
}