123 books • 14 series
Book #1: Insolitus
Book #1: Hilda and the Hidden People
Book #2: Hilda and the Great Parade
Book #3: Hilda and the Nowhere Space
Book #4: Hilda and the Time Worm
Book #6: It's Rubber
Book #45: Structural Molec Biology
Book #5: Hilda and the Ghost Ship
Book #6: Hilda and the White Woff
Book #2: Ozzie's Return