1. Nuclear Technology Section, Institute of Geological and Mining Research, Yaoundé, Cameroon
2. Laboratory of analytical, structural and material Chemistry, Department of Chemistry, Faculty of Science, The University of Douala, Douala, Cameroon
3. Nuclear Physics Laboratory, Faculty of Science, University of Yaounde I, Yaoundé, Cameroon
4. National Radiation Protection Agency, Yaoundé, Cameroon