| Issuer | Date | Desc | State | ||
| - | |
Mongolia | 7/11/1968 | sheet of 1 type | incomplete |
| - | |
Mongolia | 7/11/1968 | empty sheet (#16775) | incomplete |
| - | |
Mongolia | 8/1/1968 | empty sheet (#16776) | incomplete |
| - | |
Mongolia | 8/1/1968 | empty sheet (#16777) | incomplete |
| - | |
Mongolia | 11/20/1968 | empty sheet (#16778) | incomplete |