@article{10_4064_cm125_2_1,
     author = {Grzegorz Tomkowicz},
     title = {A free group of piecewise linear transformations},
     journal = {Colloquium Mathematicum},
     pages = {141--146},
     publisher = {mathdoc},
     volume = {125},
     number = {2},
     year = {2011},
     doi = {10.4064/cm125-2-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm125-2-1/}
}