1. Local Material Promotion Authority (MIPROMALO) Yaounde Cameroon
2. Technical University of Freiberg Freiberg Germany
3. Department of Civil Engineering National Advanced School of Public Works (ENSTP) University of Yaoundé I Yaounde Cameroon
4. School of Civil and Ressource Engineering University of Science and Technology Beijing Beijing China
5. Mineral Material Laboratory Department of Inorganic Chemistry Faculty of Science University of Yaounde Yaounde Cameroon