| Reference |
B. van Wingerden, J.T.N. Kimman, M. van Tilburg, E. Weigold, C.J. Joachain, B. Piraux and F.J. de Heer, Absolute triple- and double-differential cross sections for ionisation of helium by electron impact, J. Phys. B: At., Mol. Opt. Phys. 12, 627-631 (1979) |
