The spectroscopic evolution of the symbiotic star AG Draconis - I. The O VI Raman, Balmer, and helium emission line variations during the outburst of 2006-2008
S. N. Shore, G. M. Wahlgren, K. Genovali, S. Bernabei, P. Koubsky, M. Šlechta, P. Škoda, A. Skopal and M. Wolf
