@article{Oblak:2372,
      author        = "Oblak, E. and  Cuypers, J. and  Lampens, P. and 
                       Seggewiss, W. and  Chareton, M. and  Duval, D.",
      title         = "{Accurate Two-Colour Photometry and Astrometry for
                       HIPPARCOS Double Stars}",
      year          = "1997",
}