Cog & Oscillating Waves
60%
| Country: | Denmark |
|---|---|
| Issue: | Academy for technical sciences |
| Date: | 1987-05-04 |
| Print: | Recess |
| Perforation: | comb 12¾ |
| Emission: | Commemorative |
| Format: | Stamp |
| Face Value: | 2.50 Danish krone |
| Print run: | 4825000 |