Brinkhuis and Leereveld, 1988
From dinoflaj3
Brinkhuis, H. and Leereveld, H., 1988: Dinoflagellate cysts from the Cretaceous/Tertiary boundary sequence of El Kef, northwest Tunisia. Review of Palaeobotany and Palynology, v.56, p.5-19, pl.1-2.