Mbụ akwụkwọ (2011) , ha na-eji 1st version nke English data set, kpara nkata ugboro nke ojiji nke afọ "1880", "1912" na "1973", wee kwuo na "anyị bụ -echefu anyị n'oge gara aga ngwa ngwa afọ na-agafe "(Fig.
