@article{IVM_1964_6_a6,
     author = {F. Z. Ziatdinov},
     title = {The spectrum of a linear second-order differential operator in a {Hilbert} space of vector-functions with values in an abstract {Hilbert} {space.~I}},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {46--58},
     year = {1964},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1964_6_a6/}
}