@article{chen2019quadrilateral,
  title={Quadrilateral mesh generation I: Metric based method},
  author={Chen, Wei and Zheng, Xiaopeng and Ke, Jingyao and Lei, Na and Luo, Zhongxuan and Gu, Xianfeng},
  journal={Computer Methods in Applied Mechanics and Engineering},
  volume={356},
  pages={652--668},
  year={2019},
  publisher={Elsevier}
}