Davey and Williams, 1966a
From dinoflaj2
Davey, R.J. and Williams, G.L., 1966a: IV. The genera Hystrichosphaera and Achomosphaera. In: Davey, R.J., Downie, C., Sarjeant, W.A.S. and Williams, G.L., Studies on Mesozoic and Cainozoic dinoflagellate cysts; British Museum (Natural History) Geology, Bulletin, Supplement 3, p.28-52.
