Pollen and spore assemblages in the Luwumbu Coal Formation (Lower Karroo) of the North Luangwa Valley, Zambia, and their biostratigraphic significance.
Reference:
Utting,J. (1976)
Pollen and spore assemblages in the Luwumbu Coal Formation (Lower Karroo) of the North Luangwa Valley, Zambia, and their biostratigraphic significance. Review of Palaeobotany and Palynology
Vol. 21 P. 295- 315