Putjuso, T., and P. Sangarun. “Influence of annealing on the giant dielectric properties of CuO ceramics prepared by a simple PVA sol-gel”. Asia-Pacific Journal of Science and Technology, vol. 17, no. 2, Apr. 2017, pp. 203-10, https://so01.tci-thaijo.org/index.php/APST/article/view/82858.