Rohlin Factors, Product Factors, and Joinings for n-to-One Maps Karma DajaniJane Hawkins Indiana University Mathematics Journal 1993 text pdf 10.1512/iumj.1993.42.42012 10.1512/iumj.1993.42.42012 en Indiana Univ. Math. J. 42 (1993) 237 - 258 state-of-the-art mathematics http://iumj.org/access/