Earliest pollen-dominated microfloras from the Early Late Carboniferous of the Tian Shan Mountains, northwest China: Their significance for the origin of conifers and palaeophytogeography.
Reference:
Zhou,Y.-X. (1994)
Earliest pollen-dominated microfloras from the Early Late Carboniferous of the Tian Shan Mountains, northwest China: Their significance for the origin of conifers and palaeophytogeography. Review of Palaeobotany and Palynology
Vol. 81 # 2 P. 193- 211