K. A. Al-Taee, G. and D. S. Al-Shama, S. (2013) “Changing in Collagen Protein Due to Aging”, College of Basic Education Research Journal, 12(1), pp. 716–732. Available at: https://stats.uomosul.edu.iq/index.php/berj/article/view/38939 (Accessed: 26 October 2025).