The Fuglede–Putnam theorem for ( p , k ) -quasihyponormal operators. Kim, In Hyoun — 2006 Journal of Inequalities and Applications [electronic only]
Essential spectra of quasisimilar ( p , k ) -quasihyponormal operators. Kim, An-Hyun; Kim, In Hyoun — 2006 Journal of Inequalities and Applications [electronic only]