| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 2007 | 978-0-9712817-0-7 | John Conner · cathy folts | Breaking the Spanish Barrier: Advanced |
| 2004 | 978-0-9712817-2-1 | John Conner | Breaking the Spanish Barrier: Level I (Beginner) (Spanish Edition) |
| 2005 | 978-0-9712817-4-5 | Catherine Coursaget | Breaking the French Barrier: Level III (Advanced) |
| 2007 | 978-0-9712817-6-9 | Catherine Coursaget · Micheline Myers | Breaking The French Barrier: Level 1 Beginner (French Edition) |
| 2004 | 978-0-9712817-8-3 | John Conner | Breaking the Spanish Barrier: Level II (Intermediate) (Spanish Edition) |