Columbia subject headings:
John Paul I, Pope, 1912-1978.
John Paul II, Pope, 1920-2005.
Papacy--History--20th century.
Paul VI, Pope, 1897-1978.
Popes--Election.
Harvard subject headings:
Catholic Church--History--1965-
John Paul I, Pope, 1912-1978.
John Paul II, Pope, 1920-2005
Papacy--History--20th century
Paul VI, Pope, 1897-1978
Popes--Election
Princeton subject headings:
John Paul I, Pope, 1912-1978.
John Paul II, Pope, 1920-2005.
Papacy--History--20th century.
Paul VI, Pope, 1897-1978.
Popes--Biography.