1. Andersen, J. and Nordström, B.: 1977, Astron.Astrophys.Suppl.Ser. 29,309.
2. Andersen, J. and Nordström, B.: 1979, Inf.Bull.CD.S. 15,39.
3. Bidelman,W.P. and MacConnell, D.,J.: 1973, Astron.J. 78,687.
4. Egret,D.: 1982, IAU Symp.98 Be Stars, Jaschek,M. and Groth,H.G. eds., 23
5. Graham, J.,A.: 1970, Astron.J. 75,703.