@article{Oblak:1856,
      author        = "Oblak, E. and  Lampens, P. and  Cuypers, J. and 
                       Halbwachs, J. L. and  Martín, E. and  Seggewiss, W. and 
                       Sinachopoulos, D. and  van Dessel, E. L. and  Chareton, M.
                       and  Duval, D.",
      title         = "{CCD photometry and astrometry for visual double and
                       multiple stars of the HIPPARCOS catalogue. I. Presentation
                       of the large scale project}",
      year          = "1999",
}