Columbia subject headings:
Catholic Church. Pope (1958-1963 : John XXIII). Pacem in terris. English.
Harvard subject headings:
Catholic Church. Pacem in terris (11 Apr. 1963)
Catholic Church. Pope (1958-1963 : John XXIII). Pacem in terris.
Princeton subject headings:
Catholic Church. Pope (1958-1963 : John XXIII). Pacem in terris.
Peace--Congresses.