Bulgaria
| Country: | Bulgaria |
| Type: | Postage stamps |
| Series: | Russian spaceships Cosmos 186 and Cosmos 188 |
| Nominal: | 20 ст |
| Year: | 1967 |
| Perforation: | line 11 |
| Mintage: | 140,000 |
Russian spaceships Cosmos 186 and Cosmos 188
 Cosmos 186 and 188 Docking |  Venus 4 and orbits around Venus 1.6$ |