Structure of Certain Nonnormal Operators Horst Behncke Indiana University Mathematics Journal 1969 text pdf 10.1512/iumj.1969.18.18010 10.1512/iumj.1969.18.18010 en Indiana Univ. Math. J. 18 (1969) 103 - 107 state-of-the-art mathematics http://iumj.org/access/