South Korean archeologist Song Ki-ho, a noted professor at Seoul National University who has published several papers criticizing the Chinese government's interpretation of Balhae's history, made several visits to China in the 1990s, 2000, 2003, and 2004, examining several historical sites and museums.
Den sydkoreanske arkæolog Song Ki-ho, en kendt professor ved Seoul National University, der har udgivet flere papirer hvori han kritiserer den kinesiske regerings fortolkning af Balhae historie, har foretaget flere besøg til Kina i 1990'erne, 2000, 2003, og 2004 og undersøgt flere historiske steder og museer.