J. van Eck, F.J. de Heer and J. Kistemaker: Excitation of helium and polarization of the resulting light induced by collisions with protons and hydrogen atoms (5-35 keV)In: Atomic Collision Processes : the Proceedings of the IIIrd International Conference on the Physics of Electronic and Atomic Collisions, London, University College London, 22nd-26th July 1963 /ed. M.R.C. McDowell, North-Holland, 1964. - pp. 624-634
F.J. de Heer and J. van Eck: Excitation of Ne induced by H+ and He+ impact (5-35 keV)In: Atomic Collision Processes : the Proceedings of the Third International Conference on the Physics of Electronic and Atomic Collisions, London, 22nd-26th July, 1963 /ed. M.R.C. McDowell, North-Holland, 1964. - pp. 635-643