Katta, A., V. Vannala, K. K. Navaneethakrishnan, R. Kandasamy, B. Venkatachalam, and M. Arafath. “Coated, Uncoated Stainless Steel Ligatures Versus Self Ligation- In the Perspective of Friction”. Pakistan Orthodontic Journal, vol. 5, no. 2, Dec. 2013, pp. 60-66, https://poj.org.pk/index.php/poj/article/view/84.