Columbia subject headings:
Harvard subject headings:
Cities and towns--Social aspects--Spain--Congresses.
Cities and towns--Spain--Growth--Congresses.
Urbanization--Political aspects--Spain--Congresses.
Urbanization--Spain--History--20th century--Congresses.
Urbanization--Spain--History--21st century--Congresses.
Princeton subject headings:
Cities and towns--Social aspects--Spain--Congresses.
Cities and towns--Spain--Growth--Congresses.
Urbanization--Political aspects--Spain--Congresses.
Urbanization--Spain--History--20th century--Congresses.
Urbanization--Spain--History--21st century--Congresses.