T. Rajasivaranjan, N.R. Patel, A. Ponraj, V. Kumar, and U. Surendran. “Development and Application of SPI Generator Using Open Source for Analyzing Drought at a Varying Time Scale”. Journal of Agrometeorology 21, no. 4 (December 1, 2019): 420–426. Accessed March 27, 2025. https://journal.agrimetassociation.org/index.php/jam/article/view/276.