Oju yŏnmun changjŏn san'go (Korean: 오주연문장전산고; Hanja: 五洲衍文長箋散稿; lit.
Oju’s Rough and Scattered Writings on Collected Theories) is a general encyclopedia written by Yi Kyugyŏng during the late Joseon-era.
It spans 60 books, covering 1,417 topics from astronomy to religion.
[1] The document was lost until the 1920s, until National Script Research Institute [ko] member Kwŏn Posang (권보상) found it being used as a wrapping paper for baked chestnuts.
He took it to the Chosŏn Kwangmunhŏe [ko], an organization founded in 1910 by Choi Nam-seon to publish classical Korean literature, which confirmed its authenticity.