You can purchase a Dutch copy of the book via: https://www.boekscout.nl/shop2/boek.php?bid=10881 

About

Trolletje Toos is a childrensbook about troll Toos who feels like he doesn’t fit in with his family. One day Toos wanders around in the forest and he hears some beautiful music. When he finds the source it appears to be a magical musicbox! This musicbox gives Toos the fun again that he missed in his life!

Some Spreads

Concept Art