KUALIFIKASI WELDING PROCEDURE SPECIFICATION (WPS) DAN JURU LAS (WELDER) BERDASARKAN ASME SECTION IX DI INDUSTRI MIGAS. (2012). Swara Patra : Majalah Ilmiah PPSDM Migas, 2(3). https://dev-ejurnal.ppsdmmigas.id/sp/index.php/swarapatra/article/view/81