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Han KH, Syi JL, Brooks BR, Ferretti JA.Han KH, et al. Among authors: brooks br.Proc Natl Acad Sci U S A. 1990 Apr;87(7):2818-22. doi: 10.1073/pnas.87.7.2818.Proc Natl Acad Sci U S A. 1990.PMID: 2320585Free PMC article.
Steinbach PJ, Brooks BR.Steinbach PJ, et al. Among authors: brooks br.Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):9135-9. doi: 10.1073/pnas.90.19.9135.Proc Natl Acad Sci U S A. 1993.PMID: 8415667Free PMC article.