Veerabathini, Sairam, et al. “STANDARDIZATION OF FRIABLE CALLUS DEVELOPMENT IN CATHARANTHUS ROSEUS (LINN.) G. DON”. International Journal of Pharmacy and Pharmaceutical Sciences, vol. 7, no. 3, Mar. 2015, pp. 111-3, https://www.journals.innovareacademics.in/index.php/ijpps/article/view/4237.