Columbia subject headings:
Gran Vía (Madrid, Spain)--History--Congresses.
Streets--Spain--History--20th century--Congresses.
Harvard subject headings:
Gran Vía (Madrid, Spain)--History--Congresses.
Streets--Spain--History--20th century--Congresses.
Princeton subject headings:
Gran Vía (Madrid, Spain)--History--Congresses.
Streets--Spain--History--20th century--Congresses.