Dhaif Allah, Ali Ahmed, and Noorazuan Md. Hashim. “Analysis of Meteorological Drought in Tihama Plain, Yemen Using Standardized Precipitation Index (SPI)”.
GEOGRAFI, vol. 4, no. 2, Oct. 2016, pp. 9-20,
https://ejournal.upsi.edu.my/index.php/GEOG/article/view/1930.