Eaton et al., 2001
From dinoflaj3
Eaton, G.L., Fensome, R.A., Riding, J.B. and Williams, G.L., 2001: Re-evaluation of the status of the dinoflagellate cyst genus Cleistosphaeridium. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, v.219, nos.1-2, p.171-205.