Optical absorption spectra of finite systems from a conserving Bethe-Salpeter equation approach G. Pal, Y. Pavlyukh, W. Hübner and H. C. Schneider Eur. Phys. J. B, 79 3 (2011) 327-334 Published online: 14 January 2011 DOI: 10.1140/epjb/e2010-10033-1