L-Istati Uniti
Muri Bhalissa: L-Istati Uniti - Bolol tal-posta ta' l-ajru (1918 - 2012) - 2 bolol.
1991
William T.Piper
17. May WM: Xejn Perforazzjoni: 11
![[William T.Piper, Tip CW]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/CW-s.jpg)
1993
William T. Piper - Hair Touches Top Edge of Design
13. July WM: Xejn Perforazzjoni: 11¼
![[William T. Piper - Hair Touches Top Edge of Design, Tip CW1]](https://www.stampworld.com/media/catalogue/United-States/Airmail-stamps/CW1-s.jpg)
