1. University College London, London, UK
2. Federal Institute for Geosciences & Natural Resources, Hannover, Germany
3. Université Bourgogne de Franche-Comté, Besançon, France
4. Université de Doula, Douala, Cameroon
5. Hydrological Research Center, Yaounde, Cameroon
6. Drilling for Life, Nairobi, Kenya