1. Department of Chemistry, Faculty of Science, University of Maroua, Maroua, Cameroon
2. Department of Chemical Engineering, School of Chemical Engineering and Mineral Industries, University of Ngaoundere, Ngaoundere, Cameroon
3. Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
4. Department of Chemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
5. Department of Chemistry, Faculty of Science, Eskişehir Technical University, Eskisehir, Turkey
6. Department of Chemistry, Inorganic and Structural Chemistry, Bielefeld University, Bielefeld, Germany
7. Department of Chemistry, Higher Teachers Training College, University of Maroua, Maroua, Cameroon