@article{Bia³ynicki-Birula:1978,
  author  = "I. Bia³ynicki-Birula and V. Cao Long",
  title   = "New algorithm for numerical calculations of energies of N-level systems interacting with quantized electromagnetic field",
  journal = "Bulletin de l'Académie Polonaise des Sciences : Série des Sciences Mathématiques, Astronomiques et Physiques",
  volume  = "Vol. 26",
  number  = "no 12",
  pages   = "1051--1054",
  year    = "1978",
}