| Issuer | Date | Desc | State | ||
| - | no image | Bhutan | 1/1/1973 | empty sheet (#50636) | incomplete |
| - | no image | Bhutan | 1/1/1973 | empty sheet (#50637) | incomplete |
| - | no image | Bhutan | 1/30/1973 | empty sheet (#50638) | incomplete |
| - | no image | Bhutan | 2/28/1973 | empty sheet (#50639) | incomplete |
| - | no image | Bhutan | 2/28/1973 | empty sheet (#50640) | incomplete |
| - | no image | Bhutan | 5/2/1973 | empty sheet (#50641) | incomplete |
| - | no image | Bhutan | 9/25/1973 | empty sheet (#50642) | incomplete |
| - | no image | Bhutan | 9/25/1973 | empty sheet (#50643) | incomplete |
| - | no image | Bhutan | 11/14/1973 | empty sheet (#50644) | incomplete |