| Clue | Source | Date |
|---|---|---|
| Light units | New York Times | 17 Oct 2024 |
| Light bulb measurements | ||
| Light units | New York Times | 05 Feb 2024 |
| Bulb units | New York Times | 21 Jan 2022 |
| Unit used to measure visible light | ||
| Lightbulb units | The Washington Post Sunday | 08 Mar 2020 |
| Units of light | Premier Sunday | 21 Oct 2018 |
| Light bulb units | Wall Street Journal | 04 May 2017 |
| Measures of light | Premier Sunday | 26 Mar 2017 |
| Units of light flow | Universal | 25 Aug 2016 |
| Light bulb units | LA Times Daily | 21 Jul 2016 |
| Units of light flow | ||
| Light bulb units | ||
| Light bulb measures | Universal | 13 Oct 2015 |
| Light bulb measures | ||
| Brightness measures | ||
| Light measures | ||
| Light units | ||
| Light units | ||
| What a projector's intensity is measured in | ||
| Bulb units | ||
| Light measures | ||
| Light bulb units | ||
| Light flux units | ||
| Units of light flow | ||
| Light units. | ||
| Units of light flow. |