“The Aqueous Calyx Extract of Hibiscus sabdariffa Lowers Blood Pressure and Heart Rate via Sympathetic Nervous System Dependent Mechanisms” (2021) Nigerian Journal of Physiological Sciences, 29(2), s. 131–136. Tilgængelig hos: https://www.ojshostng.com/index.php/njphysiologicalsciences/article/view/1820 (Set: 8 juli 2026).