| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Mystical Element of Religion: Volume II. Critical Studies: v. 2 | 978-0-227-17262-9 (0-227-17262-0) | 2009 | Friedrich Hugel (Von) |
| Mystical Element of Religion: Volume I. Introduction and Biographies: v. 1 | 978-0-227-17261-2 (0-227-17261-2) | 2009 | " |