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Heupler S, Lauer M, Williams MJ, Shan K, Marwick TH.Heupler S, et al.Am Heart J. 1997 Jun;133(6):691-7. doi: 10.1016/s0002-8703(97)70171-6.Am Heart J. 1997.PMID: 9200397
Lauer MS, Pashkow FJ, Snader CE, Harvey SA, Thomas JD, Marwick TH.Lauer MS, et al.Am Heart J. 1997 Feb;133(2):139-46. doi: 10.1016/s0002-8703(97)70201-1.Am Heart J. 1997.PMID: 9023158