@article{DM_2006_18_3_a8,
     author = {V. A. Kolmykov},
     title = {Endomorphisms of functional graphs},
     journal = {Diskretnaya Matematika},
     pages = {115--119},
     publisher = {mathdoc},
     volume = {18},
     number = {3},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2006_18_3_a8/}
}