Columbia subject headings:
Jews--Poland--Economic conditions.
Poland--Economic conditions.
Schiper, Ignacy, 1884-1943.
Harvard subject headings:
Civilization, Medieval--Jewish influences
Jews--Poland--Economic conditions.
Poland--Economic conditions
Schiper, Ignacy, 1884-1943.
Princeton subject headings:
Jews--Poland--Economic conditions.
Poland--Economic conditions.
Schiper, Ignacy, 1884-1943.