@article{CHEB_2011_12_2_a18,
     author = {N. A. Shchuchkin},
     title = {The free abelian  $n$-ary groups},
     journal = {\v{C}eby\v{s}evskij sbornik},
     pages = {163--170},
     publisher = {mathdoc},
     volume = {12},
     number = {2},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CHEB_2011_12_2_a18/}
}