1. A. Dalgarno, In: Physics of Ion Ion and Electron Ion Collisions, E Brouillard and J. W. McGowan, eds., 1. Plenum Press, New York (1983)
2. P. Lenard, Wied. Ann. 51, 225 (1894)
3. P. Lenard, Ann. d. Phys. 15, 485 (1904)
4. S. Bloch, Ann. d. Phys. 38, 559 (1912)
5. J. J. Thomson, Phil. Mag. 23, 449 (1912)