Rome | Harvard University | Columbia University | Yale University | University of Paris | New York University | Stanford University | Princeton University | University of Cambridge | University of Pennsylvania | University of Michigan | University of Chicago | University of California, Berkeley | University of Toronto | Cornell University | University of Oxford | Ancient Rome | University of London | University of Oslo | Cambridge University | University of Southern California | McGill University | Johns Hopkins University | Northwestern University | University of California | Brown University | University of Queensland | University of Minnesota | University of Washington | University of Notre Dame |
After his doctorate, he completed studies and research at the Gregorian University of Rome (Italy), the University of London (United Kingdom), Georgetown University (Washington D.C., USA), the University of Ottawa (Canada), Oxford University (United Kingdom) and the University of Warwick (Coventry, United Kingdom).