Niger. University of Maradi [O. Abdou-Arbi]
Poland. Politechnika Wroclawska [W. Dyrka]
Chile. University of Chile [A. Siegel, C. Frioux, M. Aite, M. Louarn]
Poland. Politechnika Wroclawska [F. Coste]
Germany. University of Potsdam [L. Bourneuf, 3 months (nov 2017 - jan 2018)]