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Ehleringer JR, Bowen GJ, Chesson LA, West AG, Podlesak DW, Cerling TE.Ehleringer JR, et al. Among authors: chesson la.Proc Natl Acad Sci U S A. 2008 Feb 26;105(8):2788-93. doi: 10.1073/pnas.0712228105. Epub 2008 Feb 25.Proc Natl Acad Sci U S A. 2008.PMID: 18299562Free PMC article.