@article{CMH_1980__55_139839,
     author = {Raimo N\"akki and Bruce Palka},
     title = {Quasiconformal circles and {Lipschitz} classes.},
     journal = {Commentarii mathematici Helvetici},
     pages = {485--498},
     publisher = {mathdoc},
     volume = {55},
     year = {1980},
     zbl = {0447.30005},
     url = {http://geodesic.mathdoc.fr/item/CMH_1980__55_139839/}
}