http://en.wikipedia.org/wiki/Galaxy

http://www.nasa.gov/worldbook/galaxy_worldbook.html

http://www.space.com/galaxy/

http://www.seds.org/messier/galaxy.html

http://www.tripatlas.com/Galaxies

http://science.nationalgeographic.com/science/space/universe/galaxies-article.html

http://www.galaxyzooblog.org/2009/11/

http://www.sunysb.edu/library/aboutgalaxy.htm

http://www.wordiq.com/definition/Galaxy

http://web.mlsnet.com/t106/about/faq/index.jsp?about=stadium