@article{SM_1976_29_3_a9,
     author = {E. B. Rabinovich and V. Z. Feinberg},
     title = {Letter to the {Editor}},
     journal = {Sbornik. Mathematics},
     pages = {430},
     publisher = {mathdoc},
     volume = {29},
     number = {3},
     year = {1976},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1976_29_3_a9/}
}