Virani, Paras B, et al. “Development and Validation of Analytical Method for Irbesartan and Atorvastatin by Simultaneous Equation Spectroscopic Method”. International Journal of Advances in Scientific Research, vol. 1, no. 4, May 2015, pp. 194-8, https://doi.org/10.7439/ijasr.v1i4.1770.