Early Arenig acritarchs from the Leetse Formation (St. Petersburg region, northwest Russia) and their palaeogeographic significance.
Reference:
Raevskaya,E.G. (1999)
Early Arenig acritarchs from the Leetse Formation (St. Petersburg region, northwest Russia) and their palaeogeographic significance. Bollettino della SocietĀ Paleontologica Italiana
Vol. 38 # 3 P. 247- 256