@article{IVM_1959_6_a5,
     author = {L. S. Dashnits},
     title = {On the closure of certain differential operators},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {44--47},
     publisher = {mathdoc},
     number = {6},
     year = {1959},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1959_6_a5/}
}