University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Bamenda, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Pretoria - Department of Chemistry, University of Pretoria, University of Pretoria, University of Yaounde I - Faculty of Science and University of Yaounde I - Faculty of Science

University of Yaounde I, University of Yaounde I, University of Yaounde I, University of Yaounde I, affiliation not provided to SSRN, University of Yaounde I, University of Yaounde I, University of Ngaoundéré, University of Yaounde I, University of Yaounde I - Faculty of Science, University of Yaounde I - Faculty of Science, University of Bamenda and University of Yaounde I - Faculty of Science