„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), str. 131–136. Dostopno na: http://ojshostng.com/index.php/njphysiologicalsciences/article/view/1820 (Pridobljeno: 2 julij 2026).