Suanzaogou Village in Tongxin County, Ningxia Province (106.585, 37.246, Wulalike Formation)
Ge, M.Y., Zheng Z.C., Li, Y.Z. 1990. Research of Ordovician and Silurian graptolites and graptolite bearing strata from Ningxia and the neighbouring districts. Nanjing, Nanjing University Press, 1–190.