«Anti-Gastric Ulcer Effect of Betulinic Acid in Male Albino Rats» (2021) Nigerian Journal of Physiological Sciences, 30(1), or. 033–037. Available at: https://www.ojshostng.com/index.php/njphysiologicalsciences/article/view/1831 (Eskuratua: 21 maiatza 2026).