@article{10_1090_S0894_0347_2014_00796_7,
     author = {Puder, Doron and Parzanchevski, Ori},
     title = {Measure preserving words are primitive},
     journal = {Journal of the American Mathematical Society},
     pages = {63--97},
     publisher = {mathdoc},
     volume = {28},
     number = {1},
     year = {2015},
     doi = {10.1090/S0894-0347-2014-00796-7},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-2014-00796-7/}
}