Tsakiris, G. D. Laboratory for Attosecond Physics, Max Planck Institute of Quantum Optics, Max Planck Society; Laser Plasma Physics, Max Planck Institute of Quantum Optics, Max Planck Society;
Charalambidis, D., Tzallas, P., Papadogiannis, N. A., Nikolopoulos, L. A. A., Benis, E. P., & Tsakiris, G. D. (2006). Comment on "Photoionization of helium atoms irradiated with intense vacuum ultraviolet free-electron laser light. Part I. Experimental study of multiphoton and single-photon processes". Physical Review A, 74(3):. doi:10.1103/PhysRevA.74.037401.