| Clue | Source | Date |
|---|---|---|
| Self-balancing two-wheelers (TM) (7) | ||
| Motorized scooters used by some tour groups | ||
| Self-balancing transports | Universal | 20 Jul 2021 |
| Motorized two-wheelers | New York Times | 20 May 2019 |
| Motorized two-wheelers | ||
| Some city tour vehicles | The Washington Post Sunday | 03 Jun 2018 |
| Urban transports |