Davey, 1974
From dinoflaj3
Davey, R.J., 1974: Dinoflagellate cysts from the Barremian of the Speeton Clay, England. In: Symposium on Stratigraphic Palynology; Birbal Sahni Institute of Palaeobotany, Special Publication, no.3, p.41-75, pl.1-9.