Dynamics of resonant energy transfer in a cold Rydberg gas S. Westermann, T. Amthor, A. L. de Oliveira, J. Deiglmayr, M. Reetz-Lamour and M. Weidemüller Eur. Phys. J. D, 40 1 (2006) 37-43 Published online: 15 June 2006 DOI: 10.1140/epjd/e2006-00130-3