Cygnus X-3 and the problem of the missing Wolf-Rayet X-ray binaries D. Lommen, L. Yungelson, E. van den Heuvel, G. Nelemans and S. Portegies Zwart A&A, 443 1 (2005) 231-241 Published online: 21 October 2005 DOI: 10.1051/0004-6361:20052824