Patel, R P, et al. “Formulation Evaluation and Optimization of Stomach Specific In Situ Gel of Ranitidine Hydrochloride”. International Journal of Pharmaceutical Sciences and Nanotechnology(IJPSN), vol. 3, no. 1, May 2010, pp. 834-43, doi:10.37285/ijpsn.2010.3.1.6.