Keitel, Christoph H. Division Prof. Dr. Christoph H. Keitel, MPI for Nuclear Physics, Max Planck Society;
http://iopscience.iop.org/0953-4075/29/24/003/ (Verlagsversion)
Keitel, C. H. (1996). Ultra-energetic electron ejection in relativistic atom - laser field interaction. Journal of Physics B: Atomic, Molecular and Optical Physics, 29(24), L873-L880. doi:10.1088/0953-4075/29/24/003.