[2016-10-07]. (原始内容存档于2013-08-24). 请检查|date=中的日期值 (帮助) Jae Park(2013),Culturalartifact, ideology export or soft power? Confucius Institute in Peru, International
1984., p21 Bogoshi, J., Naidoo, K. and Webb, J.: "The oldest mathematical artifact", Math. Gazette, 71:458 (1987) 294. Ishango, 22000 and 50 years later: