@article{IVM_1961_6_a3,
     author = {F. Z. Ziatdinov},
     title = {On the theory of linear differential operators},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {25--31},
     publisher = {mathdoc},
     number = {6},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1961_6_a3/}
}