Details on the Dapingian are available at Wang, X.; Stouge, S.; Chen, X.; Li, Z.; Wang, C. (2009). "Dapingian Stage: standard name for the lowermost global stage of the Middle Ordovician Series". Lethaia. 42 (3): 377–380. doi:10.1111/j.1502-3931.2009.00169.x.