| details |
Late Arenigian |
|
Czechoslovakia |
VavrdovЎ,M. Nethromorphitae and some other acritarchs from the Bohemian Lower Ordovician |
1978 |
| details |
Middle Arenigian |
Late Arenigian |
Bulgaria |
Kalvacheva,R.K. Palynological evidence for the Early-Ordovician (Arenigian) age of ophiolites in the Botevgran District (West Balkan Mountain) Bulgaria. |
1982 |
| details |
Late Arenigian |
|
Bulgaria |
Kalvacheva,R.K. Palynology and stratigraphy of the Diavase-Phyllitoid complex in the West Balkan Mountains. |
1982 |
| details |
Late Arenigian |
|
Bulgaria |
Kalvacheva,R.K. Acritarch evidence for Ordovician System in West Bulgaria |
1984 |