Khalili, R. Mohd Adzim, et al. “Total Phenolic Content and In Vitro Antioxidant Activity of Winged Bean (Psophocarpus Tetragonolobus)”. Pakistan Journal of Nutrition, vol. 12, no. 5, Apr. 2013, pp. 416–422, https://doi.org/10.3923/pjn.2013.416.422.