| title | media type | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|---|
| The World of E-Government | Hardcover | 978-0-7890-2305-6 (0-7890-2305-9) | 2004 | Michael Sommer · Veronika Vis-Sommer |
| The World of E-Government | Paperback | 978-0-7890-2306-3 (0-7890-2306-7) | 2003 | Michael Sommer · Veronika Vis-Sommer |