NASA, S. (2011, September 19). Nasa science. Retrieved from http://science.nasa.gov/astrophysics/
Latta, S. (1995, September 30). In the beginning. Retrieved from http://archive.ncsa.illinois.edu/Cyberia/Cosmos/InTheBeginning.html
Hawking, S. (n.d.). All about science. Retrieved from http://www.big-bang-theory.com/
Latta, S. (1995, September 30). In the beginning. Retrieved from http://archive.ncsa.illinois.edu/Cyberia/Cosmos/InTheBeginning.html
Hawking, S. (n.d.). All about science. Retrieved from http://www.big-bang-theory.com/