Shahid, Bilal, et al. “Synthesis of Potential Biologically Active 4,5-Dimethoxy-2-[3-Oxo-3-Phenylprop-1-En-1-yl]benzene Sulfonic Acid Derivatives”. Asian Journal of Chemistry, vol. 25, no. 11, June 2013, pp. 6334-8, doi:10.14233/ajchem.2013.14534.