Global patterns of linkage disequilibrium at the CD4 locus and modem human origins - Tishkoff, S A; Dietzsch, E; Speed, W; Pakstis, A J; Kidd, J R; Cheung, K; BonneTamir, B; Santachiara-Benericetti, A S; Moral, P; Krings, M; Paabo, S; Watson, E; Risch, N; Jenkins, T; Kidd, K K (Science, 1996)