| SWEDEN | 1929 (30 May) Special flight Stockholm - Amsterdam, Netherlands (31 May) with special green cachet. Multifkd envelope, cachet reverse. |
U$ | 38 |
| SWEDEN | 1929 (30 May) Special flight Stockholm - Amsterdam, Netherlands (31 May) with special green cachet. Multifkd envelope, cachet reverse. |
U$ | 38 |