Columbia subject headings:
Castro, Américo, 1885-1972--Bibliography.
Castro, Américo, 1885-1972.
Spain--Historiography.
Spanish literature--History and criticism.
Harvard subject headings:
Castro, Américo, 1885-1972--Congresses.
Spain--Historiography--Congresses.
Princeton subject headings:
Castro, Américo, 1885-1972--Congresses.
Spain--Historiography--Congresses.