Anatolyevna Pronko, Nina, et al. “The Effect of Prolonged Irrigation on the Dry Steppe Soils’ Fertility in the Volga Region”. International Journal of Engineering & Technology, vol. 7, no. 4.38, Dec. 2018, pp. 1210-3, https://doi.org/10.14419/ijet.v7i4.38.27764.