Bachmann, P. Plasma Diagnostics Group (HUB), Max Planck Institute for Plasma Physics, Max Planck Society;
Bachmann, P., Reiter, D., & Prinja, A. K. (1992). Simple models for evaluating the role of atomic processes in helium enrichment. Journal of Nuclear Materials, 196, 865-870. doi:10.1016/S0022-3115(06)80158-3.