He also presided over the Fédération International pour le Droit Européen (FIDE); founded and presided over the Spanish Association for the Study of European Law, and took part in the Academic Council of the European Law Research Center at Harvard Law School.
Presidiu a Fédération International pour le Droit Européen (FIDE); a Asociación Española para el estudio del Derecho europeo, e pertenceu ao consello académico da Facultade de Dereito da Universidade Harvard.