Holder Continuity of Conformal Mappings at the Boundary via the Strip Method F. Lesley Indiana University Mathematics Journal 1982 text pdf 10.1512/iumj.1982.31.31030 10.1512/iumj.1982.31.31030 en Indiana Univ. Math. J. 31 (1982) 341 - 354 state-of-the-art mathematics http://iumj.org/access/