United States
Now showing: United States - Airmail stamps (1918 - 2012) - 2 stamps.
1989
The 20th UPU Congress & World Stamp Expo '89
24. November WM: None Perforation: Imperforated
![[The 20th UPU Congress & World Stamp Expo '89, type ]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/0113-b.jpg)
1989
The 20th UPU Congress
27. November WM: None Perforation: 11
![[The 20th UPU Congress, type ]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/0117-b.jpg)