1. Baldwin, J.A., Ferland, G.J., Korista, K.T., Hamann, F., Dietrich, M.: Astrophys. J. 582, 590 (2003)
2. Bertolotti, M., Scudieri, F., Verginelli, S.: Appl. Opt. 15(7), 1842 (1976)
3. Bocko, M.F., Douglass, D.H., Knox, R.S.: Phys. Rev. Lett. 58(25), 2649 (1987)
4. Cox, A.N. (ed.): Allen’s Astrophysical Quantities, 4th edn. Springer, New York (2000)
5. Dietrich, M., Wagner, S.J., Courvoisier, T.J.-L., Bock, H., North, P.: Astron. Astrophys. 351, 31 (1999)