| original |
Middle Cambrian |
|
USSR(Pre-Baltic) |
Timofeev,B.V. Ancient flora of the Prebaltic Region and its stratigraphic significance |
1959 |
| details |
Proterozoic |
Early Paleozoic |
USSR(Karelian ASSR) |
Timofeev,B.V. Stratigraphy and correlation of the Precambrian |
1960 |
| details |
Proterozoic |
|
USSR |
Potonie,R. Synopsis of the genera of the sporae dispersae. Part 4. Supplement to all Groups, (Turmae). |
1966 |
| details |
Nd |
|
Nd |
Fensome,R.A. et al. Acritarchs and Fossil Prasinophytes: An index to genera, species and infraspecific taxa. |
1990 |
| details |
Ordovician |
|
Nd |
Servais,T. An annotated bibliographical review of Ordovician acritarchs |
1997 |