| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Cosmic Dreams at Play: Guide to German Progressive and Electronic Rock | 978-1-899855-01-8 (1-899855-01-7) | 1996 |
| Scented Gardens of the Mind: A Comprehensive Guide to the Golden Era of Progressive Rock | 978-1-899855-12-4 (1-899855-12-2) | 2001 |