{"id":"001013981","type":"book","title":"Betulin, fate of a birch tar biomarker","publisher":"Archaeopress","publisher-place":"Oxford","pages":"91-95","container-title":"Archaeological sciences : 1997. Proceedings of the Conference held at the University of Durham, 2nd-4th september 1997","author":[{"family":"Ruthenberg","given":"Klaus A."}],"issued":{"raw":"2001"}}