Chernykh , E. M. “Archaeological Micro-Regions of the Ananyino Hillforts in the Udmurt Kama Region”. Arkheologiia Evraziiskikh Stepei (Archaeology of the Eurasian Steppes), no. 2, Apr. 2023, pp. 130-56, doi:10.24852/2587-6112.2023.2.130.156.