SU(2)XSU(2)-INVARIANT SCATTERING MATRIX OF THE HUBBARD-MODEL
NUCLEAR PHYSICS B 426:3 (1994) 505-533
The role of symmetries in systems of strongly correlated electrons
CORRELATION EFFECTS IN LOW-DIMENSIONAL ELECTRON SYSTEMS 118 (1994) 57-67
Scattering Matrix and Excitation Spectrum of the Hubbard Model
(1993)
Spectrum of Low-Lying Excitations in a Supersymmetric Extended Hubbard Model
(1993)