„Anti-Gastric Ulcer Effect of Betulinic Acid in Male Albino Rats" (2021) Nigerian Journal of Physiological Sciences, 30(1), s. 033–037. Dostupné z: https://www.ojshostng.com/index.php/njphysiologicalsciences/article/view/1831 (Viděno: 21 květen 2026).