Emmanuela Neoma Akaniro-Ejim and Godwill Azeh Engwa, “Polyphenol Content and in Vitro Antioxidant Activity of Aqueous-Ethanol Extracts of Pterocarpus Soyauxii and Pterocarpus Santalinoides”, GJMR, vol. 18, no. B2, pp. 1–8, Mar. 2018.