Book of Song
By the records of Samguk Sagi, he reigned from 420 to 427 AD for eight years, which can be calculated from the record. However, the Book of Song does not mention Guisin as the king and goes straight from Jeonji (written as 餘映.Read as yeoyeong) to Biyu (written as 餘毗.Read as Yeobi) Nihon Shoki accounts that Guisin was young that a Japanese figure ruled for him and quotes from a record of Baekje that is now lost.