| Clue | Source | Date |
|---|---|---|
| __ zone: shallowest oceanic region that sunlight doesn't reach | LA Times Daily | 15 Jun 2017 |
| __ zone: shallowest oceanic region that sunlight doesn't reach | The Washington Post | 15 Jun 2017 |
| __ zone: shallowest oceanic region that sunlight doesn't reach |