1. Department of Earth Resources Science Akita University Akita Japan
2. Department of Earth, Environmental and Resource Sciences The University of Texas at El Paso El Paso Texas USA
3. Eksplorasi Nusa Jaya (Affiliate of Freeport‐McMoran Inc) Jakarta Indonesia
4. Department of Geological Engineering IST AKPRIND Yogyakarta Indonesia
5. PT Agincourt Resources Batangtoru Indonesia