Gopal, G., and V. Thomas. “Localization of Peroxidase Enzyme in the Bark of Hevea Brasiliensis and Its Implication in Anatomy”. Journal of Plantation Crops, vol. 42, no. 3, July 2014, pp. 294-00, https://updatepublishing.com/journal/index.php/JPC/article/view/5623.