German hardcover 1-6. 1st editions, but post movie printing (recognized by the movie font).
3rd book is in a book club version for "RM Buch und Medien Vertrieb GmbH" from 2000 (pre-movie). It has no ISBN number, but a book number instead.
Cover illustration: Sabine Wilharm.
ISBN:
3-551-55167-7
3-551-55168-5
(Buch-NR: 060590)
3-551-55193-6
3-551-55555-9
3-551-56666-6

Softcover 6-7. Cover illustration: Sabine Wilharm.
ISBN:
978-3-551-35406-8
978-3-551-35407-5

Spell Box Set from 2013 - it has spells on the sides, so the name is very fitting! It originally came in a box that I sadly don't have.
ISBN:
 978-3-551-31311-9
978-3-551-31312-6
978-3-551-31313-3
978-3-551-31314-0
978-3-551-31315-7
978-3-551-31316-4
978-3-551-31317-1