Samguk Sagi; History of the Three Kingdoms
A historical record of the Three Kingdoms of Korea (Goguryeo, Baekje, Silla), compiled in 1145. Used as a proper noun for this specific work.
The Samguk Sagi is a historical record of the Korean Peninsula compiled during the Goryeo period.
From Korean 삼국사기 (Samguk Sagi), literally 'Historical Records of the Three Kingdoms'.