| Clue | Source | Date |
|---|---|---|
| One in EPA enforcement? | The Chronicle of Higher Education | 03 Aug 2018 |
| One in EPA enforcement? | ||
| *Enforcer of greenhouse gas restrictions? | LA Times Daily | 07 Dec 2017 |
| *Enforcer of greenhouse gas restrictions? | The Washington Post | 07 Dec 2017 |
| *Enforcer of greenhouse gas restrictions? |