  Finally, both groups created textual lineages and accounts of textual authority. In a scientific context, authoritative texts were nominally attributed to a culture hero or divine source.  Examples include the medical “classic” The Yellow Emperor's Classic of Internal Medicine (Huang Di nei jing, Unschuld 2003, Unschuld and Tessenow 2011) and the Zhou [dynasty] Classic of Gnomon Calculation (Zhou bi suan jing, Cullen 1976 and 1996). By contrast, the evidence of recently excavated texts indicates that such texts derived from prior textual traditions that were subsequently lost (Harper 1998). Other Masters created their own texts and apocryphal lineages, but did not appear to have debated each other extensively or to have taken self-consciously critical stances toward their human or textual predecessors (Lloyd 1996, Lloyd and Sivin 2002).