3rd and 4th century BC 6th century 1480 18th and 19th century 1876 1878 1880 1883 1893 1898 1900 1909 1911 1912 1914 1918 1921 1923 1924 1925 1928 1930 1932 1933 1934 1935 1936 1937 1939 1945 1948 1949 1950 1951 1952 1953 1954 1955 1957 1958 1960 1961 1963 1964 1965 1967 1968 1970 1971 1972 1973 1974 1975 1977 1978 1979 1980 1981 1982 1987 1990 1992 1997 1998 1999 Literature / Source