[4] Naitō Torajirō pointed out that the Gori Kingdom (where King Dongmyeong, a founder of Buyeo was born) was a country of Daur people who lived by Songhua River.
[6] The oldest record of King Dongmyeong, a founder of Buyeo, is in Lunheng of Wang Chong in the Eastern Han dynasty.
In Records of the Three Kingdoms, Vol30, Chapter 30 of Book of Wei, Biographics of Wuhuan, Xianbei, and Dongyi, Weilue, there's following descriptions.
昔北方有高離之國者，其王者侍婢有身，王欲殺之，婢云：「有氣如雞子來下，我故有身。」後生子，王捐之於溷中，豬以喙噓之，徙至馬閑，馬以氣噓之，不死。王疑以爲天子也，乃令其母收畜之，名曰東明，常令牧馬。東明善射，王恐奪其國也，欲殺之。東明走，南至施掩水，以弓擊水，魚鱉浮爲橋，東明得度，魚鱉乃解散，追兵不得渡。東明因都王夫餘之地。 Once upon a time, in country of Gori of Beiyi (Hanja: 北夷), the king tried to kill the maid because she gets pregnant.
The king thought that was a work of God, took him back to mother’s place, make her to raise him up, and name a boy as Dong Myeong.