Asokan, R., and N. Sivagnanam. “Objective Regionalisation of Tamil Nadu, a Southern State of India Based on Principal Component Analysis”. Vayumandal 40, no. 1-2 (February 26, 2024): 113-122. Accessed August 22, 2025. https://vayumandal.imetsociety.org/index.php/Vayumandal/article/view/159.