| Bibliography |  Suggestions |
| 1 | Lichačev, N., "Drevneyšiya bully i pečati Širpuly", Zapiski Klassičeskago Otdjelenija Imperatorskago Russkago Archeologičeskago Obščestva 4 (1907) 225-263 |
| http://oracc.museum.upenn.edu/epsd2/P142587 |
| http://cdli.ucla.edu/P142587 |