You can purchase the official printed book (with or without the CD-ROM) from a number of trusted online retailers:
"Planetino 2" is the second part of a three-level German course designed specifically for children at the primary school level. This methodically designed course aims to guide students to the A1 level of the Common European Framework of Reference for Languages (CEFR) in a child-appropriate, varied, and fun way, typically for ages 7 to 10. Planetino 2 Arbeitsbuch.pdf
Dedicated sections help non-native children master difficult German sounds, focusing on intonation and rhythm. You can purchase the official printed book (with
Gamifying vocabulary retention to lower learning anxiety. Gamifying vocabulary retention to lower learning anxiety
Visit the official Hueber website and search for ISBN 978-3-19-301577-0 (Planetino 2 Arbeitsbuch) or ask your local bookstore about the digital edition. Viel Erfolg beim Deutschlernen!