Comparison of Agrologic Knowledge in Diyuan and Yugong;

The Xu with the Inscriptions of "■公" and the Date of Yugong Written

To according with Yugong, the oldest and most important book both in geography and administration, the number of Zhou changed from 14 to 9.

As a famous book in pre-Qin literature in our country, Yugong has been put much emphasis by scholars of past generations.

The earliest courses of the lower Yellow River are: the Yugong River and Shanjing River.

Some Opinions on Liangzhou in Yugong;