@article{Lukierski:1997,
  author  = "J. Lukierski and A. Nowicki and H. Ruegg",
  title   = "Generalized deformations of D = 4 Poincaré algebra",
  journal = "Turkish Journal of Physics",
  volume  = "Vol. 21",
  number  = "no 3",
  pages   = "437--445",
  year    = "1997",
}