@article{IIGUM_2017_21_a6,
     author = {A. A. Malykh and A. V. Mantsivoda},
     title = {Document models},
     journal = {The Bulletin of Irkutsk State University. Series Mathematics},
     pages = {89--107},
     year = {2017},
     volume = {21},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IIGUM_2017_21_a6/}
}