Oommen, M., A. Sundari, and J. Thomas. “Optimisation of Foliar Application of Zinc and Boron in Small Cardamom (Elettaria Cardamomum Maton)”. Journal of Plantation Crops, vol. 39, no. 2, June 2011, pp. 285-9, https://updatepublishing.com/journal/index.php/JPC/article/view/5934.