Columbia subject headings:
Rome (Italy)--Civilization--15th century--Congresses.
Rome (Italy)--History--1420-1798--Congresses.
Sixtus IV, Pope, 1414-1484--Congresses.
Harvard subject headings:
Church history--Middle Ages, 600-1500--Congresses.
Rome (Italy)--History--1420-1798--Congresses.
Sixtus IV, Pope, 1414-1484--Congresses.
Princeton subject headings: