1. Degussa AG, Edelmetall-Taschenbuch, Hüthig-Verlag, Heidelberg, 1995
2. BeyArs Schmucklexikon, http://www.beyars.com/lexikon/lexikon_ 442.html
3. ISO 11426 (1997) “Determination of gold in gold jewellery alloys”
4. A. Marucco und W. Stankiewicz, “Development of an XRF Spectrometry analytical method for gold determination in gold jewelry alloys”.Gold Bulletin 31 (1998) 14
5. M. Brill, “Analysis of Carat Gold”,Gold technology 22 (1997), 10