Houghton Mifflin Harcourt
Harcourt: Biographies: Carl Sagan
A look at Carl Sagan, the man who brought the wonders of astronomy to the average person. Carl Sagan helped millions of people understand earth, the solar system, the universe and beyond. (In Spanish)
Other
Founder and First President of the Planetary Society
Tribute to Carl Sagan by members of the society he founded. Contains essays written by Sagan and related articles.