Pearce et al., 2011
From dinoflaj3
Pearce, M.A., Lignum, J.S. and Jarvis, I., 2011: Senoniasphaera turonica (Prössl, 1990 ex Prössl, 1992) comb. nov., senior synonym of Senoniasphaera rotundata alveolata Pearce et al., 2003: an important dinocyst marker for the Lower Turonian chalk of NW Europe. Journal of Micropalaeontology, v.30, p.91-93, pl.1.