M. M. RASHEED, A. Analysis of Rainfall Drought Periods in the North of Iraq Using Standard Precipitation Index (SPI). Al-Rafidain Engineering Journal (AREJ), [S. l.], v. 18, n. 2, p. 60–72, 2010. DOI: 10.33899/rengj.2010.28187. Disponível em: https://ojs.uomosul.edu.iq/index.php/arej/article/view/26701. Acesso em: 7 aug. 2025.