473 books • 46 series
Misterios de la Historia (History's Mysteries) (Time for Kids Nonfiction Readers: Level 4.3)
La Vida de Una Mariposa (a Butterfly's Life) (Time for Kids Nonfiction Readers: Level 1.5)
School Around the World (TIME FOR KIDS Nonfiction Readers) (TIME FOR KIDS(R) Nonfiction Readers)