Columbia subject headings:
Harvard subject headings:
Germany--Ethnic relations--History--Sources.
Germany--Ethnic relations--History.
Jewish martyrs--Germany--History--To 1500--Sources.
Jewish martyrs--Germany--History--To 1500.
Jews--Persecutions--Germany--History--To 1500--Sources.
Jews--Persecutions--Germany--History--To 1500.
Martyrdom--Judaism--Sources.
Martyrdom--Judaism.
Princeton subject headings:
Christianity--Relations--Judaism.
Crusades.
Judaism--Relations--Christianity.
Martyrdom--Judaism.