Columbia subject headings:
Belgium--Languages--History.
French language--Belgium--History.
French language--Luxembourg--History.
Germanic languages--Belgium--History.
Germanic languages--Luxembourg--History.
Languages in contact--Belgium.
Languages in contact--Luxembourg.
Luxembourg--Languages--History.
Harvard subject headings:
Belgium--Languages--History.
French language--Belgium--History.
French language--Luxembourg--History.
Germanic languages--Belgium--History.
Germanic languages--Luxembourg--History.
Languages in contact--Belgium.
Languages in contact--Luxembourg.
Luxembourg--Languages--History.
Princeton subject headings:
Belgium--Languages--History.
French language--Belgium--History.
French language--Luxembourg--History.
Germanic languages--Belgium--History.
Germanic languages--Luxembourg--History.
Languages in contact--Belgium.
Languages in contact--Luxembourg.
Luxembourg--Languages--History.