@article{IVM_1985_2_a5,
     author = {I. V. Mel'nikova},
     title = {The family $M$, $N$ of operator functions and second-order equations in {Banach} space},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {45--52},
     publisher = {mathdoc},
     number = {2},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1985_2_a5/}
}