@article{RMI_2008_2008_1_a24,
     author = {Hajlasz, P. and  Koskela, P. and  Tuominen, H. },
     title = {Measure density and extendability of {Sobolev} functions.},
     journal = {Revista matem\'atica iberoamericana},
     pages = {645-669},
     publisher = {mathdoc},
     volume = {24},
     number = {2},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RMI_2008_2008_1_a24/}
}