| 2002 |
Theorem of completeness for a Dirac type operator with generalized $lambda$-depending boundary conditions |
Hassi Seppo;Oridoroga Leonid |
| 2002 |
On the realization of inverse Stieltjes functions |
Belyi S.;Hassi Seppo;de Snoo H.S.V.;Tsekanovskii E.R. |
| 2002 |
Realizations of Herglotz-Nevanlinna functions via F-systems |
Hassi Seppo;de Snoo Henk;Tsekanovskii Eduard |
| 2002 |
Rank one perturbations in a Pontryagin space with one negative square |
Derkach, Vladimir; Hassi, Seppo; de Snoo, Henk |
| 2001 |
Singular perturbations of selfadjoint operators and their operator models |
Derkach Vladimir;Hassi Seppo;de Snoo Henk |
