Tolong jelaskan mengenai ISBN10-415-58264-4 dari Yan Xishan

Spence, Jonathan D. The Search for Modern China, W.W. Norton and Company. 1999. .

"CHINA: President Resigns."  TIME Magazine. Monday, Sep. 29, 1930. Diakses 23 Februari 2011.

"Foreign News: Yen to Nanking."  TIME Magazine. Monday, Dec. 24, 1928. p. 293. Diakses 23 Februari 2011.

"Marshal Yen Hsi-shan" . TIME Magazine. May 19, 1930. Diakses 24 Februari 2011.

Wang Ke-wen, ed. Modern China: An Encyclopedia of History, Culture, and Nationalism. United States of America: Wang Ke-wen. 1998. . Diakses 4 Juni 2012.