1 R.A. Bartels, T.C. Weinacht, M.D. Baertschy, N.L. Wagner, C.H. Greene, H.. Kapteyn, and M.. Murnane, in Unknown (Opt. Soc. America, Long Beach, CA, USA, 2002).
1 E.L. Hamilton, C.H. Greene, and H.R. Sadeghpour, Journal of Physics B: Atomic, Molecular and Optical Physics 35, (2002).