Columbia subject headings:
Catholic Church--Foreign relations.
Catholics--Europe--Biography.
Papacy--History--1799-1870.
Vrecken, Paul van der, 1777-1868.
Harvard subject headings:
Catholic Church--Foreign relations.
Catholics--Europe--Biography.
Papacy--History--1799-1870
Vrecken, Paul van der, 1777-1868.
Princeton subject headings:
Catholic Church--Foreign relations--History--Sources.
Catholic Church--History--Modern period, 1500---Sources.
Germany--Description and travel.
Italy--Description and travel.
Rome (Italy)--Description and travel.
Vrecken, Paul van der, 1777-1868.