Multiplication invariant subspaces of the Bergman space Brent CarswellPeter DurenM. Stessin Indiana University Mathematics Journal 2002 text pdf 10.1512/iumj.2002.51.2184 10.1512/iumj.2002.51.2184 en Indiana Univ. Math. J. 51 (2002) 931 - 962 state-of-the-art mathematics http://iumj.org/access/