Era
20th century
19th century
9
1949-
3
20th century --
3
1789-1900
1
1861 -1912
1
1866-1953
1
1901-1936
1
1914-1918 - Causes
1
1917
1
1937-1979
1
1945-
1
1971-1980- History and criticism
1
1979-
1
1981-1990 - History and criticism
1
20th Century
1
20th Century --
1
20th century - Biography
1
20th century - Examinations, questions, etc
1
20th century. --
1
Ch'ing dynasty
1