Columbia subject headings:
Poverty--History--Congresses.
Harvard subject headings:
Elite (Social sciences)--Congresses
Equality--Congresses
Income--Regional disparities--Congresses.
Poverty--Congresses
Princeton subject headings:
Civilization, Ancient--Congresses.
Poor--Early works to 1800--Congresses.
Poverty--Early works to 1800--Congresses.