LUBNA SHAIKH, VISHAL PANDE, and DEEPAK MUSMADE. “SYNTHESIS, CHARECTERIZATION, DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR PROCESS RELATED IMPURITY IN NIMODIPINE BULK AND FORMULATION”. International Journal of Pharmaceutics and Drug Analysis, vol. 3, no. 6, June 2015, pp. 207-13, https://www.ijpda.org/index.php/journal/article/view/159.