Completely Singular Elliptic-Harmonic Measures Luis CaffarelliE. FabesCarlos Kenig Indiana University Mathematics Journal 1981 text pdf 10.1512/iumj.1981.30.30067 10.1512/iumj.1981.30.30067 en Indiana Univ. Math. J. 30 (1981) 917 - 924 state-of-the-art mathematics http://iumj.org/access/