Columbia subject headings:
Harvard subject headings:
Alfonso X, King of Castile and Leon, 1221-1284--Influence--Congresses.
Alfonso X, King of Castile and Leon, 1221-1284. Primera crónica general--Congresses.
Castile (Spain)--Historiography--Congresses.
Historiography--Spain--Castile--History--To 1500--Congresses.
Princeton subject headings:
Alfonso X, King of Castille and Leon, 1221-1284--Congresses.