Marsch, E. MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society; Department Sun and Heliosphere, Max Planck Institute for Solar System Research, Max Planck Society;
Marsch, E. (1975). On the frequency-dependent conductivity and the current operator of the Hubbard model. Phys. Stat. Sol. (b), 72, K103-K108.