K Kandiannan, P A Mathew, C. K. T. V. S. S. H. “Evaluation of Nursery Mixture for Planting Material Production in Black Pepper (Piper Nigrum L.)”. Journal of Spices and Aromatic Crops, vol. 16, no. 2, Dec. 2007, pp. 111-4, https://updatepublishing.com/journal/index.php/josac/article/view/4874.