@article{ADM_2008_4_a1,
     author = {Taras Banakh and Volodymyr Gavrylkiv},
     title = {Algebra in superextensions of groups, {II:} cancelativity and centers},
     journal = {Algebra and discrete mathematics},
     pages = {1--14},
     publisher = {mathdoc},
     number = {4},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ADM_2008_4_a1/}
}