Hu Yunxu, 1986
From dinoflaj3
Hu Yunxu, 1986: Micropalaeoflora from the Early Ordovician in Gaoqiao Region of Shaanxi and its stratigraphic significance. Xian Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Bulletin, no.14, p.199-239, pl.1-20. (In Chinese with English summary.)