Chen, W.-Y., J.-C. Lee, H.-P. Hsu, and Y.-F. Wu. “Photoluminescence Study of Hydrothermally Grown ZnO Nanostructures”. Proceedings of Engineering and Technology Innovation, vol. 4, Oct. 2016, pp. 16-18, https://ojs.imeti.org/index.php/PETI/article/view/246.