1. Research Unit on Soil Analysis and Environmental Chemistry, Department of Soil Sciences, Faculty of Agronomy and Agricultural Sciences, University of Dschang, Dschang, Cameroon
2. Research Unit on Ecology and Applied Biology, Department of Animal Biology, Faculty of Sciences, University of Dschang, Dschang, Cameroon
3. Department of Mining and Mineral Engineering, National Higher Polytechnic Institute, University of Bamenda, Bambili, Cameroon