@incollection{Boehm-Hansford-B-patches-quadrics-91,
  mrnumber = {MR1133460},
  author = {Boehm, Wolfgang and Hansford, Dianne},
  mrclass = {53A05 (65D17)},
  booktitle = {N{URBS} for curve and surface design ({T}empe, {AZ}, 1990)},
  address = {Philadelphia, PA},
  title = {B\'ezier patches on quadrics},
  publisher = {SIAM},
  year = {1991},
  pages = {1--14},
}