V Srinivasan, K. S. R. S. B. “Evaluation of Indigenous Azospirillum Isolates for Growth Promotion in Black Pep- Per (Piper Nigrum L) Rooted Cuttings”. Journal of Spices and Aromatic Crops, vol. 17, no. 2, June 2008, pp. 128-33, https://updatepublishing.com/journal/index.php/josac/article/view/4905.