In the book "Erke. The cult of the son of heaven in North Asia" Potanin outlined in the images the legends of Mongolia, telling about Yerka, a participant in the creation of the world, the son of a creator overthrown in the underworld and waging an eternal struggle with the king of heaven. He outlined poems about the son of heaven appearing in the images of Tsoros, Irin-sain, Geser and Genghis Khan, and the rites associated with his veneration.