Jessy, M.D., A.N. Sasidharan Nair, M. Meera Bai, P. Rajendran, and K.I. Punnoose. 2009. “Self-Sustainability of Phosphorus Cycle in Rubber (Hevea Brasiliensis) Plantations: Annual Recycling through Litter and Removal through Latex”. Journal of Plantation Crops 37 (3):177-84. https://updatepublishing.com/journal/index.php/JPC/article/view/5965.