@incollection{Dahmen-piecewise-quadric-88,
  mrnumber = {MR1022707 (91a:65030)},
  author = {Dahmen, Wolfgang},
  mrclass = {65D10},
  booktitle = {Mathematical methods in computer aided geometric design ({O}slo,
               1988)},
  mrreviewer = {Jaroslaw R. Rossignac},
  address = {Boston, MA},
  title = {Smooth piecewise quadric surfaces},
  publisher = {Academic Press},
  year = {1989},
  pages = {181--193},
}