| Clue | Source | Date |
|---|---|---|
| Quantum theory founder | Wall Street Journal | 05 Sep 2023 |
| Quantum theory pioneer | LA Times Daily | 20 Sep 2015 |
| Quantum theory pioneer | ||
| German physics Nobelist | ||
| Quantum theory pioneer | ||
| 1918 winner who discovered energy quanta | ||
| Quantum theory developer. | ||
| Pioneering quantum theorist |