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Chazan, Michael; Ron, Hagai; Matmon, Ari; Porat, Naomi; Goldberg, Paul; Yates, Royden; Avery, Margaret; Sumner, Alexandra; Horwitz, Liora Kolska (2008). "Radiometric dating of the Earlier Stone Age sequence in Excavation I at Wonderwerk Cave, South Africa: preliminary results". Journal of Human Evolution. 55 (1): 1-11. doi:10.1016/j.jhevol.2008.01.004. ISSN0047-2484. PMID18501953.
Chazan, Michael; Ron, Hagai; Matmon, Ari; Porat, Naomi; Goldberg, Paul; Yates, Royden; Avery, Margaret; Sumner, Alexandra; Horwitz, Liora Kolska (2008). "Radiometric dating of the Earlier Stone Age sequence in Excavation I at Wonderwerk Cave, South Africa: preliminary results". Journal of Human Evolution. 55 (1): 1-11. doi:10.1016/j.jhevol.2008.01.004. ISSN0047-2484. PMID18501953.