Electronic spectrum in a microscopical model for the Zn-doped CuO2 plane Ž. Kovačević, I. Chaplygin, R. Hayn and N. M. Plakida Eur. Phys. J. B, 18 3 (2000) 377-384 Published online: 15 December 2000 DOI: 10.1007/s100510070022