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Stone AF, Risley P, Markus HS, Butland BK, Strachan DP, Elwood PC, Mendall MA.Stone AF, et al. Among authors: elwood pc.Heart. 2001 Nov;86(5):506-9. doi: 10.1136/heart.86.5.506.Heart. 2001.PMID: 11602541Free PMC article.