A Topological Three Pole Theorem James Jenkins Indiana University Mathematics Journal 1972 text pdf 10.1512/iumj.1972.21.21081 10.1512/iumj.1972.21.21081 en Indiana Univ. Math. J. 21 (1972) 1013 - 1018 state-of-the-art mathematics http://iumj.org/access/