@article{Boehm-quadrics-92,
  volume = {10},
  number = {3-4},
  mrnumber = {MR1235154 (95c:51030)},
  issn = {0167-8396},
  author = {Boehm, Wolfgang},
  mrclass = {51N20 (65Y25)},
  note = {Free-form curves and free-form surfaces (Oberwolfach, 1992)},
  fjournal = {Computer Aided Geometric Design},
  coden = {CAGDEX},
  title = {Some remarks on quadrics},
  journal = {Comput. Aided Geom. Design},
  year = {1993},
  pages = {231--236},
}