“Formulation Evaluation Development and Validation of Simultaneous Equation Method for Estimation of Vitamin C and Vitamin D in Multivitamin Lipstick”. Asian Journal of Pharmaceutical and Health Sciences 10, no. 2 (June 30, 2020): 2239–2247. Accessed September 23, 2025. https://ajphs.com/index.php/ajphs/article/view/204.