@article{VKAM_2016_1_a1,
     author = {A. P. Goryushkin},
     title = {Index of a subgroup finding and occurence problem},
     journal = {Vestnik KRAUNC. Fiziko-matemati\v{c}eskie nauki},
     pages = {15--25},
     publisher = {mathdoc},
     number = {1},
     year = {2016},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VKAM_2016_1_a1/}
}