The Bloch Constant of Bounded Harmonic Mappings Flavia Colonna Indiana University Mathematics Journal 1989 text pdf 10.1512/iumj.1989.38.38039 10.1512/iumj.1989.38.38039 en Indiana Univ. Math. J. 38 (1989) 829 - 840 state-of-the-art mathematics http://iumj.org/access/