1. Laboratory of Forest Resources and Wood Valorisation, Training Unit for Engineering Sciences, Post Graduate School of Fundamental and Applied Sciences, University of Douala, Douala, Cameroon
2. Transport and Applied Logistics Laboratory, Post Graduate School of Fundamental and Applied Sciences, Training Unit for Pure Sciences University of Douala, Douala, Cameroon
3. Department of Mechanical Engineering, Faculty of Engineering and Technology, University of Buea, Buea, Cameroon