1. Barbier, R., Swings, J.P., 1982, in Jaschek, M., Groth, H.-G., eds, Be Stars, IAU Symp. 98, D.Reidel, Dordrecht, p. 103
2. Brandi, E., Garcia, L.G., Piirola, V., Scaltriti, E, Quiroga, C., 2000, AandAS, 145, 197
3. Carter, B.S., 1990, MNRAS, 242, 1
4. Corradi, R.L.M., Schwarz, H., 2000, AandA, 363, 671
5. Harries, T.J., Howarth, I.D., 1996, AandAS, 119, 61