en Semaw, S.; Rogers, M. J.; Quade, J.; Renne, P. R.; Butler, R. F.; Domínguez-Rodrigo, M.; Stout, D.; Hart, W. S.; Pickering, T.; et al. (). „2.6-Million-year-old stone tools and associated bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia”. Journal of Human Evolution. 45 (2): 169–177. doi:10.1016/S0047-2484(03)00093-9. PMID14529651.
en Semaw, S.; Rogers, M. J.; Quade, J.; Renne, P. R.; Butler, R. F.; Domínguez-Rodrigo, M.; Stout, D.; Hart, W. S.; Pickering, T.; et al. (). „2.6-Million-year-old stone tools and associated bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia”. Journal of Human Evolution. 45 (2): 169–177. doi:10.1016/S0047-2484(03)00093-9. PMID14529651.
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