@article{Cao Long:1989,
  author  = "V. Cao Long and C. Nguyen Huy",
  title   = "(N-1)-resonant n-photon ionization in the presence of pre-gaussian field",
  journal = "Acta Physica Polonica A",
  volume  = "Vol. A76",
  number  = "no 5",
  pages   = "719--734",
  year    = "1989",
}