| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 1992 | 978-0-910542-01-2 | Educational Services Teaching Cassettes | Arabic Language 30 |
| 1975 | 978-0-910542-03-6 | Educational Services | Language/30 Danish: a Conversation Course using a Proven Self-Learning Method; Two Audio Cassettes, and a Phrase Dictionary and Study Guide |
| 1992 | 978-0-910542-57-9 | Language 30 | Japanese: Start Speaking Today! (Language/30) |
| 1994 | 978-0-910542-72-2 | Language 30 | Vietnamese: Start Speaking Today (Language/30) |
| 1990 | 978-0-910542-76-0 | '' | Danish: Language 30 |
| 1995 | 978-0-910542-83-8 | Educational Services | Polish: Language 30 (Polish Edition) |
| '' | 978-0-910542-87-6 | Language 30 | Hungarian: Start Speaking Today (Language 30) |
| '' | 978-0-910542-89-0 | Educational Services | Latin: Start Speaking Today! (Language 30) (English and Latin Edition) |
| '' | 978-0-910542-90-6 | Educational Service | Yiddish: Language 30 |