1. Hypercontractions and subnormality;Agler;J. Operator Theory,1985
2. Subnormal operators with compact selfcommutator;Aleman;Manuscripta Math.,1996
3. Subnormal operators;Bram;Duke Math. J.,1955
4. Linear operators for which T∗T and T+T∗ commute. II;Campbell;Trans. Amer. Math. Soc.,1977
5. The Theory of Subnormal Operators;Conway,1991