Kukreti, V., and R.P. Chamoli. “A Study on the Synthesis of New Phthalides Derived from 2-(3,4-Dimethylbenzoyl)benzoic Acid”. Asian Journal of Chemistry, vol. 9, no. 1, Mar. 2010, pp. 66-69, https://asianpubs.org/index.php/ajchem/article/view/23813.