Semaw, Sileshi (בדצמבר 2000). "The World's Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago". Journal of Archaeological Science. 27 (12): 1197–1214. doi:10.1006/jasc.1999.0592. ISSN0305-4403. {{cite journal}}: (עזרה)
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Ricardo Soca, Africa, La Palbra del Dia, 7-6-2024
Semaw, Sileshi (בדצמבר 2000). "The World's Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago". Journal of Archaeological Science. 27 (12): 1197–1214. doi:10.1006/jasc.1999.0592. ISSN0305-4403. {{cite journal}}: (עזרה)