Old English, ca. 450-1100 (150)
Ottoman Empire, 1288-1918 (148)
Old High German, 750-1050 (21)
Occupation, 1939-1945 (18)
Osakuntatalo. (15)
Old Kingdom, ca. 2686-ca. 2181 B.C (9)
Occupation, 1941-1944 (7)
Opium War, 1840-1842 (6)
Orange Revolution, 2004. (6)
Old English, approximately 450-1100 (5)
October Crisis, 1970. (4)
Ordovician (4)
Orange Revolution, 2004 (3)
Oulu (2)
Obras anteriores a 1800. (1)
Obras anteriores al S XVIII (1)
October Crisis, 1970 (1)
Ocupación británica, 1765-1947 (1)
Oligocene (1)
Ontario (1)
Origin and antecedents (1)
Osakuntatalo (1)
Ostia (1)
Otto I, 936-973 (1)
Oulun lääni (1)
Overthrow of the Monarchy, 1893. (1)