About “Prime Tortoise of the Record Bureau”
Cefu Yuangui is the largest leishu, or encyclopedia, compiled during the Chinese Song dynasty (AD 960–1279). It was the last of the Four Great Books of Song, the previous three having been published in the 10th century. (Summary adapted from Wikipedia, CC BY-SA 4.0.)
Some summaries adapted from Wikipedia, CC BY-SA 4.0.