Maheshwari, R.K., and Mahaveer Singh. “Quantitative Determination of Ketoprofen Bulk Drug Using Sodium Salt of Aspirin As Hydrotropic Solubilizing Agent”. Asian Journal of Chemistry, vol. 20, no. 6, Mar. 2010, pp. 4922-4, https://asianpubs.org/index.php/ajchem/article/view/19118.