@incollection{Lyche-Morken-94-Metric,
  mrnumber = {MR1302212 (95g:65027)},
  author = {Lyche, Tom and M{\o}rken, Knut},
  mrclass = {65D17 (65Y25)},
  booktitle = {Curves and surfaces in geometric design (Chamonix-Mont-Blanc,
               1993)},
  address = {Wellesley, MA},
  title = {A metric for parametric approximation},
  publisher = {A K Peters},
  year = {1994},
  pages = {311--318},
}