Chowdary, K.P.R., and V. Galibsaheb. “Formulation and Evaluation of Floating Tablets of Diltiazem Employing Olibanum Gum”. Asian Journal of Chemistry, vol. 22, no. 7, June 2010, pp. 5277-81, https://asianpubs.org/index.php/ajchem/article/view/11744.