Syamsudin, et al. “Heme Polymerization Inhibitory Activities of Xanthone from G. Parvifolia (Miq) Miq Stem Bark As an Antimalarial Agent”. Asian Journal of Chemistry, vol. 25, no. 3, Oct. 2012, pp. 1311-4, doi:10.14233/ajchem.2013.12962.