Columbia subject headings:
Crusades--Third, 1189-1192--Sources.
Frederick I, Holy Roman Emperor, approximately 1123-1190--Manuscripts.
Holy Roman Empire--History--Frederick I, 1152-1190--Sources.
Italy--History--Germanic rule, 962-1268--Sources.
Lombardy (Italy)--History--To 1535--Sources.
Manuscripts, Medieval.
Harvard subject headings:
Frederick I, Holy Roman Emperor, approximately 1123-1190.
Lombardy (Italy)--History--Sources.
Princeton subject headings:
Frederick I, Holy Roman Emperor, approximately 1123-1190.
Lombardy (Italy)--History--Sources.