พุกอินทร์ อ. อ. “Nam Phi Steel – Thai Sustainable Quality Steel”. Research Journal Phranakhon Rajabhat : Science and Technology, vol. 12, no. 1, June 2017, pp. 120-8, https://li01.tci-thaijo.org/index.php/PRRJ_Scitech/article/view/72181.