Grigelis, A. A.; Mesezhnikov, M. S.; Yakovleva, S. P.; Kozlova, G. E. (1977). First finds of planktonic foraminifera in the Upper Jurassic of the Pechora River Basin. Akademya Nauk SSSR Doklady, Geol. 233(5): 926-927.
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Grigelis, A. A.; Mesezhnikov, M. S.; Yakovleva, S. P.; Kozlova, G. E.
1977
First finds of planktonic foraminifera in the Upper Jurassic of the Pechora River Basin