Los Reyes, Mariquit M. De, et al. “Cytotoxic Prenylflavanones from Philippine Stingless Bee (Tetragonula Biroi Friese) Nests”. Asian Journal of Chemistry, vol. 30, no. 3, Jan. 2018, pp. 613-9, doi:10.14233/ajchem.2018.21053.