1973, a nearly complete book of changes in the second century BC was unearthed in Mawangdui, Changsha, Hunan Province, which is the earliest existing version. Compared with today's edition, this edition only includes the upper and lower parts of Cohesion Biography, excluding other parts of Ten Wings.
No Zhouyi was unearthed in the Western Zhou Dynasty. It is generally believed in academic circles that the Book of Changes was written in the late Western Zhou Dynasty, not by Zhou Wenwang alone.