Prysiazhniuk, V. A. “Mollusks of the Subgenus Planivallonia S C H I L E Y K O, 1984 (Mollusca, Pulmonata) from the Neogene Deposits of Ukraine, Russia, and Kazakhstan”. Reports of the National Academy of Sciences of Ukraine, no. 2, Sept. 2024, pp. 75-78, doi:10.15407/dopovidi2016.02.075.