Marwoto, Putut, et al. “Study of Zno:Ga Thin Film Structure With Variation of Plasma Power Using the DC Magnetron Sputtering Method”. Journal of Natural Sciences and Mathematics Research, vol. 4, no. 2, Dec. 2018, pp. 41-46, https://journal.walisongo.ac.id/index.php/JNSMR/article/view/11017.