@article{VMUMM_1989_5_a3,
     author = {S. A. Bogatyi},
     title = {Periodic points of a mapping of a tree},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {16--18},
     publisher = {mathdoc},
     number = {5},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1989_5_a3/}
}