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| ƒ/€ | Description: | # |  |
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| 12+8 C | Isometric projection from circle to square | 1.100.000 | 0.30 € | 0.25 € |
| 15+10 C | Parallel surfaces in a cube | 1.000.000 | 0.30 € | 0.25 € |
| 20+10 C | Two scale divisions | 1.100.000 | 0.30 € | 0.25 € |
| 25+10 C | Transition phases from concentric circles | 1.600.000 | 0.30 € | 0.10 € |
| 45+20 C | Interference pattern | 1.000.000 | 0.30 € | 0.25 € |
| Series: | 1.50 € | 1.10 € | ||
| NVPH First Day Cover Nr.104 | 2.75 € | - |
| Unstamped WITH gum |
| Used |