“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), hlm. 131–136. Tersedia pada: https://ojshostng.com/index.php/njphysiologicalsciences/article/view/1820 (Diakses: 25 April 2026).