Columbia subject headings:
Harvard subject headings:
China--Capital and capitol.
Luoyang (Henan Sheng, China)--Historical geography.
Xi'an (Shaanxi Sheng, China)--Historical geography.
Princeton subject headings:
China--Capital and capitol.
Luoyang (Henan Sheng, China)--Historical geography.
Xi'an (Shaanxi Sheng, China)--Historical geography.