Columbia subject headings:
Harvard subject headings:
Cities and towns, Medieval--Congresses
Civilization, Medieval--Congresses
Diffusion of innovations--History--To 1500--Congresses.
Emigration and immigration--History--To 1500--Congresses.
Social mobility--History--To 1500--Congresses.
Princeton subject headings:
Cities and towns--Congresses.
Emigration and immigration--Congresses.
Social mobility--Congresses.