Columbia subject headings:
Vatican Council (2nd : 1962-1965 : Basilica di San Pietro in Vaticano)
Harvard subject headings:
Vatican Council (2nd : 1962-1965 : Basilica di San Pietro in Vaticano)
Vatican Council (2nd : 1962-1965 : Basilica di San Pietro in Vaticano). Decretum de oecumenismo.
Princeton subject headings: