BUMA Australia Pty Ltd (BUMA Australia) BUMA International Group DOID Perpanjangan Kontrak Tambang Goonyella Riverside PT BUMA Internasional Grup Tbk PT Bukit Makmur Mandiri Utama (BUMA) Mitsubishi Alliance (BMA) Blackwater Operations Pty Ltd TEC Coal Pty Ltd Whitehaven Coal Mining Limited kontrak kerja pertambangan