Kazak, M., S. Selin Koymen, R. Yurdan, K. Tekdemir, and N. Donmez. “Effect of Thermal Aging Procedure on the Microhardness and Surface Roughness of Fluoride Containing Materials”. Annals of Medical Research, vol. 27, no. 3, May 2021, pp. 0888-94, http://www.annalsmedres.org/index.php/aomr/article/view/656.