1960 Paraguay
1961 Paraguay
1918 Russia
1966 Paraguay
1922 Armenia
1962 Paraguay
1958 Saar
1968 Paraguay
1965 Paraguay
1963 Paraguay
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.