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Grover PL, Sims P, Huberman E, Marquardt H, Kuroki T, Heidelberger C.Grover PL, et al. Among authors: heidelberger c.Proc Natl Acad Sci U S A. 1971 Jun;68(6):1098-101. doi: 10.1073/pnas.68.6.1098.Proc Natl Acad Sci U S A. 1971.PMID: 4108174Free PMC article.