@article{SEMR_2009_6_a7,
     author = {A. N. Plyushchenko},
     title = {Overlap-free words and free {Burnside} semigroup with two generators satisfying $x^2=x^3$.},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {166--181},
     publisher = {mathdoc},
     volume = {6},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2009_6_a7/}
}