@article{ADM_2010_10_2_a7,
     author = {A. Oliynyk},
     title = {Free semigroups in wreath powers of transformation semigroups},
     journal = {Algebra and discrete mathematics},
     pages = {96--106},
     year = {2010},
     volume = {10},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ADM_2010_10_2_a7/}
}