Ramu, B., S. Kumar, G. Srikanth, and B. Rajkamal. “Formulation and Evaluation of Sustained Release Verapamil Hydrochloride Using Natural Polymers”. INTERNATIONAL JOURNAL OF APPLIED PHARMACEUTICAL SCIENCES AND RESEARCH, Vol. 1, no. 02, June 2016, pp. 76-87, doi:10.21477/ijapsr.v1i2.10179.