D. Richter & others (8 June 2017). "The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age". Nature. 546 (7657): 293–296. doi:10.1038/nature22335. PMID28593967. S2CID205255853..
D. Richter & others (8 June 2017). "The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age". Nature. 546 (7657): 293–296. doi:10.1038/nature22335. PMID28593967. S2CID205255853..
D. Richter & others (8 June 2017). "The Age of Hominin Fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age". Nature. 546 (7657): 293–296. doi:10.1038/nature22335. PMID28593967. S2CID205255853..
stratigraphy.org
stratigraphy.org
Cohen, K. M.; Finney, S. C.; Gibbard, P. L.; Fan, J.-X. (January 2020). "International Chronostratigraphic Chart"(PDF). International Commission on Stratigraphy. สืบค้นเมื่อ 23 February 2020.