| title | ISBN-13 (ISBN-10) | year of publication | |
|---|---|---|---|
| GNU/Linux-Zertifizierung, Bd.1, Installation und Konfiguration | 978-3-932588-86-0 (3-932588-86-X) | 2001 | |
| Sair Linux and GNU Certification Level 1, Security, Ethics & Privacy | 978-0-471-36975-2 (0-471-36975-6) | 2001 | |
| Sair Linux and GNU Certification Level 1, System Administration | 978-0-471-36976-9 (0-471-36976-4) | 2000 |