Columbia subject headings:
Crusades.
Syria--Economic conditions.
Syria--History--750-1260.
Harvard subject headings:
Crusades--Economic aspects.
Islamic Empire--Economic conditions.
Jerusalem--Economic conditions.
Jerusalem--History--Latin Kingdom, 1099-1244.
Syria--Economic conditions.
Princeton subject headings:
Crusades--Economic aspects.
Islamic Empire--Economic conditions.
Jerusalem--Economic conditions.
Jerusalem--History--Latin Kingdom, 1099-1244.
Syria--Economic conditions.