@article{SM_1974_24_4_a7,
     author = {Yu. I. Lyubich},
     title = {Two-level {Bernsteinian} populations},
     journal = {Sbornik. Mathematics},
     pages = {593--615},
     publisher = {mathdoc},
     volume = {24},
     number = {4},
     year = {1974},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_24_4_a7/}
}