Polygons with Parallel Opposite Sides

@article{Craizer2013PolygonsWP,
  title={Polygons with Parallel Opposite Sides},
  author={Marcos Craizer and Ralph Teixeira and Moacyr A. H. B. da Silva},
  journal={Discrete & Computational Geometry},
  year={2013},
  volume={50},
  pages={474-490}
}