@article{MZ_1962__80_170087,
     author = {B.H. Neumann and Hanna Neumann and Peter M. Neumann},
     title = {Wreath products and varieties of groups.},
     journal = {Mathematische Zeitschrift},
     pages = {44--62},
     publisher = {mathdoc},
     volume = {80},
     year = {1962},
     zbl = {0105.02003},
     url = {http://geodesic.mathdoc.fr/item/MZ_1962__80_170087/}
}