@article{IVM_1976_2_a19,
     author = {B. A. Rozenfel'd and M. P. Zamakhovskii},
     title = {Letter to the editors},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {123},
     publisher = {mathdoc},
     number = {2},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1976_2_a19/}
}