Dating of the Cretaceous Une Formaiton, Colombia and the relationship with the Albian-Cenomanian African-South American microfloral Province.
Reference:
Herngreen,G.F.W. et al. (1990)
Dating of the Cretaceous Une Formaiton, Colombia and the relationship with the Albian-Cenomanian African-South American microfloral Province. Review of Palaeobotany and Palynology
Vol. 66 # 3 P. 345- 359