| Clue | Source | Date |
|---|---|---|
| Google Books __ Viewer: tool that tracks word usage frequency | LA Times Daily | 26 Jun 2025 |
| Google ___ Viewer (tool for charting word frequency over time) | New York Times | 18 Apr 2023 |
| Google ___ Viewer (tool for charting word frequency over time) | New York Times | 09 Oct 2017 |
| Google ___ Viewer (tool for charting word frequency over time) |