1. Ore Processing Laboratory (LTM) Institute of Geological and Mining Research (IRGM) Yaoundé Cameroon
2. Department of Earth Sciences University of Yaoundé 1 Yaoundé Cameroon
3. Department of Earth Sciences University of Ngaoundéré Ngaoundéré Cameroon
4. Centre for Geological and Mining Research Institute of Geological and Mining Research Garoua Cameroon