@article{MZM_1988_43_3_a7,
     author = {S. A. Bogatyi and E. T. Shavgulidze},
     title = {Periodic points of a map of a system of intervals},
     journal = {Matemati\v{c}eskie zametki},
     pages = {365--381},
     publisher = {mathdoc},
     volume = {43},
     number = {3},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1988_43_3_a7/}
}