@conference{4474,
  author = {S. Kwok and Bruce Hrivnak and K. Volk},
  title = {Nebular properties of proto-planetary nebulae},
  year = {1990},
  publisher = {Gif-sur-Yvette, France, Editions Frontieres},
  address = {Montpellier, France},
  note = {JILA Pub. 4177},
}