| year of publication | ISBN | author(s) | title |
|---|---|---|---|
| 1998 | 978-1-891991-00-4 | Opus Educational Software | The English Teacher for Spanish-Speakers |
| '' | 978-1-891991-01-1 | '' | The English Teacher for Portuguese-Speakers |
| '' | 978-1-891991-02-8 | '' | The Spanish Teacher for English-speakers |