Thirupathi, G., et al. “Facile Synthesis and Biological Evaluation of Substituted 5-(1H-Indol-3-Ylmethylene) Pyrimidine-2,4,6-Trione Derivatives Using L-Tyrosine in Aqueous Medium”. Asian Journal of Chemistry, vol. 25, no. 15, Sept. 2013, pp. 8741-8, doi:10.14233/ajchem.2013.15364.