SULTANA, Y., K. KOHLI, R. KHAR AND, and M. AQIL. “Preparation and Dissolution Characteristics of Sustained Release Diltiazem Hydrochloride Tablets”. The East and Central African Journal of Pharmaceutical Sciences, Vol. 9, no. 2, Nov. 2018, pp. 40-45, https://uonjournals.uonbi.ac.ke/ojs/index.php/ecajps/article/view/42.