H.G. · Helen Gillespie · Helen Glasspoole · Helena Gillespie
| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Handling Data: Ages 8-9 | 978-1-4081-0040-0 (1-4081-0040-1) | 2009 |
| Handling Data: Ages 9-10 | 978-1-4081-0039-4 (1-4081-0039-8) | 2009 |
| Handling Data: Ages 10-11 | 978-1-4081-0045-5 (1-4081-0045-2) | 2009 |