1. Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
2. University of Yaoundé I, Higher Teacher Training College, P.O. Box 47, Yaoundé, Cameroon
3. University of Dschang, Electrochemistry and Chemistry of Materials, Department of Chemistry, Dschang, Cameroon
4. Michigan State University, Department of Fisheries and Wildlife, 293 Farm Lane East Lansing, MI, 22101, USA