| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Number World: Bk. 5: For Children Who Need Support in Mathematics | 978-1-898255-38-3 (1-898255-38-5) | 2002 |
| Number World: Bk. 6: For Children Who Need Support in Mathematics | 978-1-898255-39-0 (1-898255-39-3) | 2002 |
| Spelling World: Bk. 1 | 978-1-898255-01-7 (1-898255-01-6) | 1994 |