1. R.D. Cowan, The Theory of Atomic Structure and Spectra, 4th edn. (University of California Press, Berkeley, 2001)
2. I.I. Sobelman, Atomic Spectra and Radiative Transitions, 2nd edn. (Springer, Berlin, 1996)
3. L.J. Curtis, Atomic Structure and Lifetimes (Cambridge University Press, Cambridge, 2003)
4. A. Kramida’s version for Windows is from http://das101.isan.troitsk.ru/COWAN
5. I.P. Grant, Relativistic Quantum Theory of Atoms and Molecules (Springer, New York, 2007)