@article{JEMS_2003_5_2_a0,
     author = {Pekka Koskela and Jan Mal\'y},
     title = {Mappings of finite distortion: {The} zero set of the {Jacobian}},
     journal = {Journal of the European Mathematical Society},
     pages = {95--105},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {2003},
     doi = {10.1007/s10097-002-0046-9},
     url = {http://geodesic.mathdoc.fr/articles/10.1007/s10097-002-0046-9/}
}