When is a planet not a planet? : the story of Pluto /
by Elaine Scott.
- New York : Clarion Books, c2007.
- 43 p. : ill. (some col.) ; 26 cm.
Includes bibliographical references and index.
Introduction --The wanderers -- Some early astronomers -- Ideas that work--and those that don't -- Pluto's problems -- Finding planets -- What is a planet?