Columbia subject headings:
Harvard subject headings:
Trương, P. J. B. Vĩnh Ký (Pétrus Jean-Baptiste Vĩnh Ký), 1837-1898--Journeys--Vietnam--Tonkin.
Vietnam, Northern--Description and travel.
Princeton subject headings:
Trương, P. J. B. Vĩnh Ký (Pétrus Jean-Baptiste Vĩnh Ký), 1837-1898.
Vietnam (Democratic Republic)--Description and travel.