1. Baade, D., 1987, inThe Physics of Be Stars (CUP), 361.
2. Balona, L.A., 1990,Mon. Not. Roy. Astron. Soc.,245, 92.
3. Percy, J.R. and Attard, A., 1992,Publ. Astron. Soc. Pacific,104, 1160.
4. Percy, J.R., Coffin, B.L., Drukier, G.A., Ford, P., Plume, R., Ricker, M.G. and Spalding, R., 1988,Publ. Astron. Soc. Pacific,100, 1555.
5. Percy, J.R. and Peters, G.J., 1991, inRapid Variability of OB Stars: Nature and Diagnostic Value, ESO Conf. and Workshop Proceedings36, 97.