Columbia subject headings:
Harvard subject headings:
Xu, Shichang, 1855-1939
Yan, Dunyuan, 1869-1932.
Yuan, Shikai, 1859-1916
Princeton subject headings:
Xu, Shichang, 1855-1939.
Yan, Dunyuan, 1869-1932.
Yuan, Shikai, 1859-1916.