Deunff, J., Gorka, H. & Rauscher, R. (1974). Observations nouvelles et precisions sur les Acritarches a large ouverture polaire du Paleozoique inferieur. Translated Title: New observations and details on lower Paleozoic acritarchs with large polar apertures. Geobios. 7(1): 5-18. gs

Missing or ambiguous references: Vardova 1966;