Report No. 199: "The Biru Prospect" final report
Report No. 66 Coal survey Tebo Area: PT Riotinto Bethlehem Indonesia
Report No. 46 The Siulak Deras Cu / Mo anomaly final report: PT Riotinto Bethlehem Indonesia
The discovery and exploration of Pinang Coal deposit, East Kalimantan
Report No. 71 Coal Survey South Tigapuluh Mountains: PT Riotinto Bethlehem Indonesia