Tài liệu tham khảo

WikiPedia: Thiên_văn_học http://www.literature.at/elib/index.php5?title=Ast... http://www.astro.queensu.ca/~hanes/p014/Notes/Topi... http://www.astropix.com/ http://www.europhysicsnews.com/full/20/article8/ar... http://books.google.com/books?id=4DJpDW6IAukC&pg=P... http://books.google.com/books?id=Pk-bZMS_KdUC&pg=P... http://www.lunar-occultations.com/iota/iotandx.htm http://www.m-w.com/dictionary/astronomy http://www.m-w.com/dictionary/astrophysics http://www.nature.com/news/einstein-s-gravitationa...