@article{AL_2009_48_5_a3,
     author = {V. M. Kopytov},
     title = {Contractions of infrainvariant systems of subgroups},
     journal = {Algebra i logika},
     pages = {606--627},
     publisher = {mathdoc},
     volume = {48},
     number = {5},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2009_48_5_a3/}
}