1. Biota of European Russia at the Early-Late Permian Transition (Geos, Moscow, 1988) [in Russian]
2. M. F. Bogoslovskaya, “The Upper Boundary of the Lower Series of the Permian System Based on Ammonoid Data,” in Permian System: Stratigraphic Problems and Development of the Organic World (Kazan. Univ., Kazan, 1988), pp. 16–26.
3. M. F. Bogoslovskaya, “Ammonoids from Permian Sediments of Poi-Khoi and Vaigach Island,” Paleontol. Zh., No. 6, 23–28 (1997).
4. A. S. Byakov, Doctorate Dissertation in Geology and Mineralogy (St. Petersburg, VSEGEI, 2008).
5. V. I. Chalyshev and L. M. Varyukhina, Permian Biostratigraphy of the Northeastern European USSR (Nauka, Leningrad, 1968) [in Russian].