Columbia subject headings:
Baltic States--History.
Church history--Middle Ages, 600-1500.
Crusades.
Iberia (Kingdom)--History.
Harvard subject headings:
Baltic States--History.
Church history--Middle Ages, 600-1500
Crusades
I=Iberian Peninsula--History.
Princeton subject headings:
Baltic States--History.
Church history--Middle Ages, 600-1500.
Crusades.
Iberia (Kingdom)--History.