Columbia subject headings:
France--History--Raoul, 923-936--Sources.
France--History--Robert I, 922-923--Sources.
Harvard subject headings:
France. Sovereign (922-923 : Robert I)
France. Sovereign (923-936 : Raoul)
Law, Medieval.
Law--France--History
Raoul, King of France, -936.
Robert I, King of France, -923.
Princeton subject headings:
France--History--Raoul, 923-936--Sources.
France--History--Robert I, 922-923--Sources.