| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Letters to a Spiritual Seeker | 978-0-393-32756-4 (0-393-32756-6) | 2005 | Henry David Thoreau |
| Letters To A Spiritual Seeker | 978-0-393-05941-0 (0-393-05941-3) | 2004 | Henry David Thoreau · Harrison G. Blake |