PUTRI, K. D.; NORA ANISA BR. SINULINGGA. The Effect of Training and the Implementation of Occupational Health and Safety Systems on Employee Productivity of PT. PP. London Sumatra Indonesia Tbk Branch Office Medan. Journal of Economics and Business (JECOMBI), [S. l.], v. 2, n. 1, p. 66–76, 2020. DOI: 10.58471/jecombi.v2i1.9. Disponível em: https://jecombi.seaninstitute.or.id/index.php/JECOMBI/article/view/9. Acesso em: 26 may. 2026.