Absolute chronology of the Neolithic and Eneolithic cultures in the valley of Struma - Bojadžiev, Javor (The Struma/Strymon River Valley in prehistory. Proceedings of the International Symposium Strymon Praehistoricus, Kjustendil-Blagoevgrad (Bulgaria), Serres-Amphipolis (Greece), 27.09.-01.10.2004., 2007)