1. G�mez, A.E. & Crifo, F.: 1988, IAU Symposium No 133 ?Mapping the Sky?, Paris (F), to be published.
2. R�qui�me, Y.,: 1985, Proceedings of the HIPPARCOS ColloquiumScientific Aspects of the Input Catalogue Preparation?, Aussois (F), pub. ESA SP-234, 193, C. Turon & M.A.C. Perryman, eds.
3. Turon, C. & R�qui�me, Y.: 1986, IAU Symposium No 109, Gainesville (USA), p. 605, H. Eichhorn, ed.
4. Turon, C.: 1988, IAU Symposium No 133 ?Mapping the Sky?, Paris (F), to be published.
5. Turon, C. & Crifo, F.: 1986,Highlights of Astronomy, 7, 683, J.P. Swings, ed., Reidel pub.