Cyclic Vectors and Seminormal Operators Kevin ClanceyD. Rogers Indiana University Mathematics Journal 1978 text pdf 10.1512/iumj.1978.27.27045 10.1512/iumj.1978.27.27045 en Indiana Univ. Math. J. 27 (1978) 689 - 696 state-of-the-art mathematics http://iumj.org/access/