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AK 21–5: non-preferential Levallois core, recurrent centripetal, maybe a prepared Nubian core or an abandoned one (from Al-Kharj 21 site considered as a northern extension of Al-Kharj 22 site); AK 22–26: Preferential Levallois core with unidirectional convergent preparation; AK 22–51: Preferential Levallois core with centripetal preparation; AK 22–61: Recurrent centripetal non-preferential Levallois core. Drawings by G. Devilder, CNRS.
