Williams and Downie, 1966a
From dinoflaj3
Williams, G.L. and Downie, C., 1966a: The genus Hystrichokolpoma. In: Davey, R.J. and Downie, C. and Sarjeant, W.A.S. and Williams, G.L., Studies on Mesozoic and Cainozoic dinoflagellate cysts; Bulletin of the British Museum (Natural History) Geology, Supplement 3, p.176-181.