VIDYA DIGHE, et al. “Quantitation Of Camptothecin From Ervatamia Heyneana (Wall.) T. Cooke Stem Powder Using High Performance Thin Layer Chromatography”. International Journal of Pharma and Bio Sciences, vol. 3, no. 3, Sept. 2012, pp. 230-7, https://ijpbs.net/index.php/journal/article/view/1477.