A History of the Jewish People / Ben-Sasson, H.. — Cambridge: Harvard University Press, 1976. — С. 401. — ISBN 0674397304.. — «Western Europe suffered virtual famine for many years in the tenth and eleventh centuries, there is no hint or echo of this in the Jewish sources of the region in this period. They lived at an aristocratic level, as befitted international merchants and honored local financiers.».
