1. 1) R. Payling, D. Jones and A. Bengtson: Glow Discharge Optical Emission Spectrometry, John Wiley & Sons, Chichester, (1997), 497.
2. 2) R. K. Marcus and J. A. C. Broekaert: Glow Discharge Plasmas in Analytical Spectroscopy, John Wiley & Sons, Chichester, (2003), 113.
3. 3) T. Nelis and R. Payling: Glow Discharge Optical Emission Spectrometry: A Practical Guide, RSC Analytical Spectroscopy Monographs, Royal Society of Chemistry, Cambridge, (2003), 123.
4. 4) K. Wagatsuma: High Temp. Mater. Process., 17 (1998), 97.
5. 5) K. Wagatsuma and H. Matsuta: Spectrochim. Acta, Part B, 54 (1999), 527.