Riding et al., 1985
From dinoflaj3
Riding, J.B., Penn, I.E. and Woollam, R., 1985: Dinoflagellate cysts from the type area of the Bathonian Stage (Middle Jurassic; southwest England). Review of Palaeobotany and Palynology, v.45, p.149-169, pl.1-5.