and S. Srinivas, L.G.K. Naidu, K.M. Nair. 2014. “Rubber-Growing Areas of Kerala and Tamil Nadu: Soil Related Constraints to Rubber Productivity and Delineation of Soil Management Units”. Journal of the Indian Society of Soil Science 62 (1). https://epubs.icar.org.in/index.php/JISSS/article/view/41249.