Age models and the Younger Dryas Impact Hypothesis Blaauw, Maarten ; Holliday, Vance T. ; Gill, Jacquelyn L. ; Nicoll, Kathleen Abstract Publication: Proceedings of the National Academy of Science Pub Date: August 2012 DOI: 10.1073/pnas.1206143109 Bibcode: 2012PNAS..109E2240B