The Riddle of Humanity: The Spiritual Background to Human History (The Collected Works of Rudolf Steiner Book 170)
| Country | USA |
| Brand | ExpertPower |
| Manufacturer | ExpertPower |
| Binding | Electronics |
| Size | 1 Battery |
| UnitCount | 1 |
| UPCs | 840140948264 |
| EANs | 0840140948264 |
| ReleaseDate | 0000-00-00 |