| Clue | Source | Date |
|---|---|---|
| Functional unit of a kidney | Premier Sunday | 24 Apr 2022 |
| A functional unit of the kidney | The Times Specialist Sunday | 24 Nov 2019 |
| Kidney unit | Wall Street Journal | 20 Feb 2019 |
| Kidney unit | ||
| Functional unit in kidney of a vertebrate | The Telegraph General Knowledge | 14 Jun 2015 |