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Thornhill R, Fincher CL.Thornhill R, et al.Philos Trans R Soc Lond B Biol Sci. 2011 Dec 12;366(1583):3466-77. doi: 10.1098/rstb.2011.0052.Philos Trans R Soc Lond B Biol Sci. 2011.PMID: 22042922Free PMC article.Review.