Ahmad Yusof, H., R. Singh, Z. Zafarina, K. Rooney, and A. M. Che Muhamed. “The Angiotensin Converting Enzyme (ACE) I/D Gene Polymorphism In Malaysian Well Trained Athletes”. Jurnal Sains Sukan & Pendidikan Jasmani, vol. 3, no. 1, Dec. 2014, pp. 20-33, https://ojs.upsi.edu.my/index.php/JSSPJ/article/view/634.