| title | ISBN-13 | year of publication |
|---|---|---|
| He Is Your Brother: 2 | 978-0-525-66495-6 | 1976 |
| Pirate Slave: 2 | 978-0-525-66517-5 | 1977 |
| Quarter Boy: 2 | 978-0-525-66522-9 | 1976 |
| Spell of Seven: 2 | 978-0-525-66117-7 | 1971 |
| Three by Mistake: 2 | 978-0-525-66417-8 | 1974 |
R. P. · R Parker · Robert P. · Robert Parker · S. P. · S. Parker · S R · S R P · S. R. Parker · S. Robert · Stanley Parker · Stanley R. Parker