These authors' works have the subjects "quests," "courage in children," and "child heroes."

These authors' works have the genres "easy readers" and "humorous stories"; and the subjects "schools," "twelve-year-old girls," and "parallel universes."

These authors' works have the appeal factors plot-driven, and they have the genres "easy readers" and "fantasy fiction"; and the subjects "girls" and "self-reliance in children."

These authors' works have the subjects "quests," "courage," and "dragons."

These authors' works have the subjects "quests," "magical books," and "child adventurers."

These authors' works have the appeal factors action-packed, and they have the genre "historical fantasy"; and the subjects "quests," "parallel universes," and "good and evil."

These authors' works have the genre "historical fantasy"; and the subjects "locks and keys," "twelve-year-old girls," and "child adventurers."