Department of Marine engineering Limbe Nautical Arts and Fisheries Institute P.O.Box.485 Limbe Cameroon;
Department of Physics Faculty of Science University of Maroua P.O.Box 814 Maroua Cameroon;
Department of Physics Higher Teachers Training College University of Maroua P.O.Box 55 Maroua Cameroon;
Department of Physics Faculty of Science University of Ngaoundere P.O.Box 454 Ngaoundre Cameroon;
