Токарський, В. А., В. І. Ронкін, and Г. О. Савченко. “Stationary Environmental Studies of the Gully Steppe of Northeastern Ukraine: Preliminary Results of the 25-Year Observations”. The Journal of V.N.Karazin Kharkiv National University. Series «Biology», Vol. 25, 1, pp. 216-22, https://periodicals.karazin.ua/biology/article/view/5675.