| Clue | Source | Date |
|---|---|---|
| *Portable appointment calendar | Wall Street Journal | 18 Feb 2020 |
| Appointment tracker | Eugene Sheffer | 24 Jan 2019 |
| Filofax offering | Wall Street Journal | 20 Nov 2015 |
| Filofax offering | ||
| You can plan on it | ||
| Planning aid | ||
| You can plan on it | ||
| Planning aid | ||
| Planning aid |