Below is a list of references and additional resources.

• Fraknoi, Morrison, and Wolf. "The Birth of Stars and the Discovery of Planets Outside Our Solar System," Voyages to the Stars and Galaxies, 3rd edition, (2004)
• Bennett, Donahue, Schneider, and Voit. "Life Beyond Earth," The Solar System, The Cosmic Perspective, 3rd edition, (2004)
• Naeye, Robert. "Planetary Harmony," Sky and Telescope, (January 2005)
• Ward, Dennis. Searching for Extrasolar Planets, (2002).
• California and Carnegie Planet Search.http://www.exoplanets.org
• Extrasolar Visions.http://www.extrasolar.net
• STARE Project.http://www.hao.ucar.edu/public/research/stare/stare.html