Linked-solenoid mappings and the non-transversality locus invariant John HubbardRalph Oberste-Vorth Indiana University Mathematics Journal 2001 text pdf 10.1512/iumj.2001.50.1949 10.1512/iumj.2001.50.1949 en Indiana Univ. Math. J. 50 (2001) 553 - 566 state-of-the-art mathematics http://iumj.org/access/