Columbia subject headings:
Korea--Relations--Japan--Tsushima Island.
So family.
Tsushima Island (Japan)--History.
Tsushima Island (Japan)--Relations--Korea.
Harvard subject headings:
Sō family.
Tsushima-han (Japan)--History.
Tsushima-han (Japan)--Relations--Korea.
Princeton subject headings:
Sō family.
Tsushima-han (Japan)--History.
Tsushima-han (Japan)--Relations--Korea.