{"id":"001302711","type":"book","title":"Palaeoecological studies at the Kaliakra area, northeastern Bulgarian Black Sea coast: 6000 years of natural and anthropological change","pages":"29-40","container-title":"Vegetation History and Archaeobotany, 20,1 (2011","author":[{"family":"Tonkov","given":"Spassimir"}],"issued":{"raw":"2011"}}