“In vitro, antioxidant activities of aqueous and methanol roselle (Hibiscus sabdariffa) calyces extracts from two localities in Cameroon”, Nor. Afr. J. Food Nutr. Res., vol. 4, no. 8, pp. 292–297, Sep. 2020, doi: 10.51745/najfnr.4.8.292-297.