| title | ISBN-13 | year of publica- tion | other author(s) | |
|---|---|---|---|---|
| Gedanken-Striche | 978-3-924077-48-8 | 1997 | ||
| Mindmapping: Your Personal Guide to Exploring Creativity and Problem-Solving | 978-0-425-12780-3 | 1991 | ||
| To Do Doing Done | 978-0-684-81887-0 | 1997 | G. Lynne Snead | |
| Transformation Thinking | 978-0-425-14374-2 | 1995 | ||