Far-infrared optical excitations in multiferroic TbMnO3 M. Schmidt, Ch. Kant, T. Rudolf, F. Mayr, A. A. Mukhin, A. M. Balbashov, J. Deisenhofer and A. Loidl Eur. Phys. J. B, 71 3 (2009) 411-418 Published online: 23 June 2009 DOI: 10.1140/epjb/e2009-00215-3