Davey and Williams, 1966b
From dinoflaj3
Davey, R.J. and Williams, G.L., 1966b: V. The genus Hystrichosphaeridium and its allies. 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.53-106.