@article{SEMR_2005_2_a21,
     author = {M. N. Ivko},
     title = {Characterizations of some types of $SF$ groups},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {308--324},
     publisher = {mathdoc},
     volume = {2},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2005_2_a21/}
}