Columbia subject headings:
Alfonso X, King of Castile and Leon, 1221-1284.
James I, King of Aragon, 1208-1276.
Spain--History--711-1516.
Harvard subject headings:
Alfonso X, King of Castile and Leon, 1221-1284.
James I, King of Aragon, 1208-1276.
Learning and scholarship--History--Medieval, 500-1500
Spain--History--711-1516.
Princeton subject headings:
Alfonso X, King of Castile and Leon, 1221-1284.
James I, King of Aragon, 1208-1276.
Spain--History--711-1516.