@article{Wolberg-shape-preserving-2002,
  volume = {143},
  number = {2},
  mrnumber = {MR1905739 (2004b:65016)},
  issn = {0377-0427},
  author = {Wolberg, George and Alfy, Itzik},
  mrclass = {65D07 (41A15 65D05)},
  fjournal = {Journal of Computational and Applied Mathematics},
  coden = {JCAMDI},
  title = {An energy-minimization framework for monotonic cubic spline
           interpolation},
  pages = {145--188},
  journal = {J. Comput. Appl. Math.},
  year = {2002},
}