The ROSAT all-sky survey catalogue of optically bright OB-type stars T. W. Berghöfer, J. H.M.M. Schmitt and J. P. Cassinelli Astron. Astrophys. Suppl. Ser., 118 3 (1996) 481-494 Published online: 15 September 1996 DOI: 10.1051/aas:1996213