«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. Tilgjengelig på: https://ojshostng.com/index.php/njphysiologicalsciences/article/view/1820 (åpnet: 25 april 2026).