(EN) Benjamin W. Roberts, Christopher P. Thornton, Development of metallurgy in Eurasia, Department of Prehistory and Europe, British Museum, 2009, p. 1015.
«In contrast, the earliest exploitation and working of gold occurs in the Balkans during the mid-fifth millennium BC, several centuries after the earliest known copper smelting. This is demonstrated most spectacularly in the various objects adorning the burials at Varna, Bulgaria (Renfrew 1986; Highamet al. 2007). In contrast, the earliest gold objects found in Southwest Asia date only to the beginning of the fourth millennium BC as at Nahal Qanah in Israel (Golden 2009), suggesting that gold exploitation may have been a Southeast European invention, albeit a short-lived one»