28 books • 14 series
National Geographic Kids Readers: African-American History Makers (Readers BIOS) (Readers BIOS) (Readers)
Helen Keller (Readers BIOS) (National Geographic Readers) (National Geographic Readers - Level 2)
National Geographic Readers: Helen Keller (Level 2) (Readers BIOS) (National Geographic Kids Readers: Level 2)
National Geographic Kids Chapters: Danger on the Mountain (National Geographic Kids Chapters) (NGK Chapters)