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