@inproceedings{Prautzsch1999Triangular,
  Author = {Hartmut Prautzsch and Georg Umlauf},
  Title = {Triangular G<sup>2</sup>-splines},
  Booktitle = {},
  Year = {1999},
  Note = {In: P.-L. Laurent, P. Sablonniere, L. L. Schumaker (eds.), Curve and Surface Design, Vanderbilt University Press, 1999: 335–342}
}