Quasiconformal Mappings and Capacity Tadeusz IwaniecGaven Martin Indiana University Mathematics Journal 1991 text pdf 10.1512/iumj.1991.40.40005 10.1512/iumj.1991.40.40005 en Indiana Univ. Math. J. 40 (1991) 101 - 122 state-of-the-art mathematics http://iumj.org/access/