@article{AL_2009_48_2_a4,
     author = {A. Yu. Olshanskii and M. V. Sapir},
     title = {$k${-Free-like} groups},
     journal = {Algebra i logika},
     pages = {245--257},
     publisher = {mathdoc},
     volume = {48},
     number = {2},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2009_48_2_a4/}
}