МатвеевA. В. 2017. “Development Features of Calcareous Nannoplankton in Southern and Eastern Ukraine in Cretaceous Period”. Visnyk of V. N. Karazin Kharkiv National University, Series "Geology. Geography. Ecology", no. 45 (March), 53-61. https://periodicals.karazin.ua/geoeco/article/view/8181.