In which ancient book did the word "Han" first appear?

There are 1, 1903. According to Han Jingchun and Li Yifu of the Institute of Ethnic Studies of China Academy of Social Sciences, Huang Zunxian first used the word "Han nationality" and wrote it in 1903 "Refuting the Revolution": "Those who advocate nationality are unwilling to be ruled by Han nationality, Xianbei nationality and Mongolian nationality, and are not exempted from being ruled by Teutonic nationality, Slavic nationality and Latin nationality." Some scholars believe that the name "Han nationality" was first recorded in "Letters to Consuls of Various Countries" written by Li Shixian, a courtier in the late Taiping Heavenly Kingdom. In fact, there is a word "Han".