C. G. · Carl Olav Gram Gjesdal · Christian Gram
| title | media type | ISBN-13 | year of publication |
|---|---|---|---|
| Soundwaves | Audio CD | 978-0-07-329051-5 | 2007 |
| Soundwaves: Test Book 3 | Paperback | 978-0-07-333247-5 | 2008 |
| Soundwaves: Test Book Bk. 2 | Hardcover | 978-0-07-126725-0 | 2008 |
| Soundwaves: Test Book Bk. 2 | Paperback | 978-0-07-333246-8 | 2007 |
| Soundwaves: Test Book Bk. 3 | Hardcover | 978-0-07-126726-7 | 2008 |
| Soundwaves: Test Book with Audio CD 1 | " | 978-0-07-126724-3 | 2008 |