| 10. Forschungsbericht | (2003 - 2006) | Research Report No 10 |
| 9. Forschungsbericht | (2000 - 2003) | Research Report No 9 |
| 8. Forschungsbericht | (1997 - 2000) | Research Report No 8 |
| 7. Forschungsbericht | (1994 - 1997) | Research Report No 7 |
| 6. Forschungsbericht | (1991 - 1994) | Research Report No 6 |