Tài liệu tham khảo

WikiPedia: HD_40307 http://www.latimes.com/news/science/sciencenow/la-... http://www.msnbc.msn.com/id/25191635/ http://www.solstation.com/stars2/hd40307.htm http://www.space.com/18390-super-earth-exoplanet-h... http://www.space.com/18393-alien-planet-super-eart... http://adsabs.harvard.edu/abs/1915JRASC...9..203C http://adsabs.harvard.edu/abs/1918AnHar..91....1C http://adsabs.harvard.edu/abs/1918AnHar..92....1C http://adsabs.harvard.edu/abs/1919AnHar..93....1C http://adsabs.harvard.edu/abs/1919AnHar..94....1C