Shape-preserving interpolation of irregular data by bivariate curvature-based cubic L1 splines in spherical coordinates

@article{Lavery2005ShapepreservingIO,
  title={Shape-preserving interpolation of irregular data by bivariate curvature-based cubic L1 splines in spherical coordinates},
  author={John E. Lavery},
  journal={Computer Aided Geometric Design},
  year={2005},
  volume={22},
  pages={818-837}
}