Kuryshchuk, Serhii, Taras Kovalyuk, Ivan Koziarskyi, and Mykhailo Solovan. “Structural, Electrical and Optical Properties of Graphite Films Are Drawn With Pencils of Different Hardness”. East European Journal of Physics, no. 3 (September 2, 2022): 91-96. Accessed April 19, 2024. https://periodicals.karazin.ua/eejp/article/view/18822.