@article{Konacki:1999,
  author  = "M. Konacki and A. Maciejewski and A. Wolszczan",
  title   = "Resonance in PSR B1257 + 12 planetary system",
  journal = "Astrophysical Journal",
  number  = "no 513",
  pages   = "471--476",
  year    = "1999",
}