Harmonic extensions of quasiconformal maps to hyperbolic space Robert HardtMichael Wolf Indiana University Mathematics Journal 1997 text pdf 10.1512/iumj.1997.46.1351 10.1512/iumj.1997.46.1351 en Indiana Univ. Math. J. 46 (1997) 155 - 164 state-of-the-art mathematics http://iumj.org/access/