1947 Poland
1942 Belgian Congo
1942-52 Belgian Congo
1968 Canada
1922 Armenia
1953 Poland
1935 Denmark
1967 Romania
1961 Great Britain
1964 Greece
1971 Albania
1963 Denmark
1958 Pakistan
1942 Great Britain
1983 Solomon Islands
1883-96 Austria
1930-34 Austria
1943-45 Algeria
First commemorative stamps of the 20th century.
Columbus stamp promoted the 1893 Chicago World Columbian Exposition.
A single stamp to cover the one-pound air parcel rate in 1952.