@article{4377,
  author = {M. de Kool},
  title = {Common envelope evolution and double cores of planetary nebulae},
  year = {1990},
  journal = {The Astrophysical Journal},
  volume = {358},
  pages = {189},
  month = {Jan-08-1990},
  issn = {0004-637X},
  url = {http://adsabs.harvard.edu/full/1990ApJ...358..189D},
  doi = {10.1086/168974},
}