@article{Sznajd:1987,
  author  = "J. Sznajd and G. Kontrym-Sznajd and A. Drzewiński",
  title   = "Renormalization group approach to antiferromagnetic quantum XY model on a triangular lattice",
  journal = "Physica Status Solidi B-Basic Research",
  volume  = "Vol. 140",
  pages   = "155--160",
  year    = "1987",
}