U B V absolute CCD photometry and differential astrometry of a sample of visual double stars with A-type primariesN. Shatsky, D. Sinachopoulos, P. Prado and E. van DesselAstron. Astrophys. Suppl. Ser., 139 1 (1999) 69-74DOI: https://doi.org/10.1051/aas:1999380