An EPR study of Er3+ impurities in RbTiOPO4 single crystals D. Bravo, A. Martín, J. J. Carvajal, M. Aguiló, F. Díaz and F. J. López Eur. Phys. J. B, 58 3 (2007) 237-242 Published online: 08 September 2007 DOI: 10.1140/epjb/e2007-00231-3