@article{VNGU_2010_10_2_a4,
     author = {F. A. Dudkin and V. A. Churkin},
     title = {The {Number} of {Finite} {Index} {Subgroups} of {Baumslag--Solitar} {Groups}},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {54--60},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {2010},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2010_10_2_a4/}
}