Conference Paper
Kucharek, H.; Möbius, E.; Li, W.; Farrugia, C.; Popecki, M. A.; Galvin, A. B.; Klecker, B.; Hilchenbach, M.; Bochsler, P.: Relative abundance variations of energetic He
+ and He
2+ in CME related SEP events. In: Proceedings of the Tenth International Solar Wind Conference, Pisa, Italy, 17-21 June 2002, pp. 648 - 651 (Eds. Velli, M.; Bruno, R.; Malara, F.). American Institute of Physics, Melville, New York (2003)