Bouherour, Soraya, Heinz Berke, and Hans-Georg Wiedemann. “Ancient Man-Made Copper Silicate Pigments Studied by Raman Microscopy”. CHIMIA 55, no. 11 (November 28, 2001): 942. Accessed April 30, 2025. https://www.chimia.ch/chimia/article/view/2001_942.