SULISTYO, Rafiq; SOEDJARNO, Alibasjah; SIMATUPANG, Togar M. Operations Strategy Formulation: Shifting from Grasberg Open-Pit Surface Mining to Underground Mining. International Research Journal of Business Studies, Jakarta, Indonesia, v. 4, n. 1, p. 21–48, 2011. DOI: 10.21632/irjbs.4.1.21-48. Disponível em: https://irjbs.prasetiyamulya.ac.id/index.php/jurnalirjbs/article/view/801. Acesso em: 4 dec. 2025.