Tykoezinski et al., 2001
From dinoflaj3
Tykoezinski, H.R.G., Smith, S.W., Hogg, N.M. and Bailey, D.A., 2001: Three new dinoflagellate cyst species from the Bathonian and Callovian of England. Palynology, v.24, p.79-93, pl.1-4.