31 Randsborg, K. 2005 Liga. Copper age strategies in Bulgaria Merkyte I., 2005 Acta Archaeologica Copenhagen Blackwell Munksgarrd 76 (supplemento VI) 149 Età del Bronzo, Bulgaria BZ Acta Archaeologica vol 76;1, 2005 Acta Archaeologica Supplementa VI Centre of World Acrhaeology (CWA) - Pubblication 2 Liga Copper age strategies in Bulgaria"