Zawadiak, Jan, et al. “Synthesis and Properties of Aromatic 1,3-Diketones and Bis-(1,3-Diketones) Obtained from Acetophenone and Phtalic Acids Esters”. European Journal of Chemistry, vol. 2, no. 3, Sept. 2011, pp. 289-94, doi:10.5155/eurjchem.2.3.289-294.416.