Mohammed, Safwan A., and Endre Harsányi. “Drought Cycle Tracking in Hungary Using Standardized Precipitation Index (SPI)”. Acta Agraria Debreceniensis, no. 2 (December 15, 2019): 97–101. Accessed May 4, 2024. https://ojs.lib.unideb.hu/actaagrar/article/view/3685.