| details |
Middle Gothlandian |
|
Canada(Quebec) |
Cramer,F.H. Distribution of selected Silurian acritarchs an account of the palynostratigraphy and paleogeography of selected Silurian acritarch Taxa |
1970 |
| details |
Llandoverian |
Wenlockian |
USA |
Cramer,F.H. et al. North American Silurian palynofacies and their spatial arrangement. |
1972 |
| details |
Silurian |
|
USSR(Baltic) |
Bagdasaryan,L.L. The significance of microphytofossils in the solving of some problems in petroleum geology. (In: Mikrofitofossilii v neftyanoi geologii. N. A. Timoshina, editor) |
1980 |