Ferrari Bravo, Luigi Keywords: International customary law | Public international law | Mots clefs: Droit coutumier international | Droit international public | ABSTRACT Luigi Ferrari Bravo, Professor at the University of Rome, examines in his course the manifestations of the practice of States with regard to research methodologies of international custom (diplomatic and legislative practice, jurisprudence of national courts, practice of international negotiations ...). The author devotes an important place to the pra…