"Main satellites of the planets." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Dec. 2009 <http://www.encyclopedia.com>.
"Main satellites of the planets." A Dictionary of Astronomy. 1997. Encyclopedia.com. (December 1, 2009). http://www.encyclopedia.com/doc/1O80-Mainsatellitesoftheplants.html
"Main satellites of the planets." A Dictionary of Astronomy. 1997. Retrieved December 01, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-Mainsatellitesoftheplants.html