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http://en.wikipedia.org/wiki/Cosmology
http://en.wikipedia.org/wiki/Physical_cosmology
http://www.astro.ucla.edu/~wright/cosmolog.htm
http://www.jb.man.ac.uk/public/im/astbook/Ast_Apdf.pdf
https://www.ras.org.uk/publications/other-publications/2028-cosmology
http://www.if.ufrgs.br/oei/santiago/fis02012/Introduction-Cosmology-Ryde...
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