1. E. Biemont, C.F. Fischer, M. Godefroid, N. Vaeck, A. Hibbert, Proceedings of the meeting on atomic data and oscillator strengths for Astrophysical and fusion research, edited by J.E. Hansen (North-Holland, Amsterdam, 1989) p. 59
2. D.S. Leckrone, S. Johansson, R.L. Kurucz, S.J. Adelman, Proceedings of the meeting on atomic data and oscillator strengths for Astrophysical and fusion research, edited by J.E. Hansen (North-Holland, Amsterdam, 1990)
3. D.R. Beck, C.A. Nicolaides, J. Quant. Spectrosc. Radiat. Transfer. 16, 297 (1976)
4. B.C. Fawcett, At. Data Nucl. Data Tabl. 37, 411 (1987)
5. D. Hofsaess, J. Quant. Spectrosc. Radiat. Transfer 42, 45 (1989)