References: https://www.bl.uk/history-of-writing/... https://www.wondriumdaily.com/origin-... https://www.science.org/content/artic... https://blogs.illinois.edu/view/25/2751 • Washoe, Koko, and the social exchange of l... https://www.science.org/doi/10.1126/s... https://www.discovery.com/scie
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