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Alpert E, Isselbacher KJ.Alpert E, et al.Lancet. 1971 Nov 13;2(7733):1087. doi: 10.1016/s0140-6736(71)90399-0.Lancet. 1971.PMID: 4106926No abstract available.
Vrba R, Alpert E, Isselbacher KJ.Vrba R, et al. Among authors: alpert e.Proc Natl Acad Sci U S A. 1975 Nov;72(11):4602-6. doi: 10.1073/pnas.72.11.4602.Proc Natl Acad Sci U S A. 1975.PMID: 53843Free PMC article.