@article{gu2008manifold,
  title={Manifold splines with a single extraordinary point},
  author={Gu, Xianfeng and He, Ying and Jin, Miao and Luo, Feng and Qin, Hong and Yau, Shing-Tung},
  journal={Computer-Aided Design},
  volume={40},
  number={6},
  pages={676--690},
  year={2008},
  publisher={Elsevier}
}