@article{AFM_1981_6_2_a9,
     author = {P. Tukia and J. V\"ais\"al\"a},
     title = {Lipschitz and quasiconformal approximation and extension},
     journal = {Annales Fennici Mathematici},
     pages = {303--342},
     publisher = {mathdoc},
     volume = {6},
     number = {2},
     year = {1981},
     doi = {10.5186/aasfm.1981.0626},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1981.0626/}
}