"Elliptical Galaxies." Elliptical Galaxies. N.p., n.d. Web. 10 May 2015.
"ESA - Space for Kids - Our Universe - The Big Bang." ESA - Space for Kids - Our Universe - The Big Bang. N.p., n.d. Web. 10 May 2015.
"Hertzsprung-Russell Diagram." Hertzsprung-Russell Diagram. N.p., n.d. Web. 07 May 2015.
"Galaxy Formation." Galaxy Formation. N.p., n.d. Web. 07 May 2015.
"HubbleSite - Reference Desk - FAQs." HubbleSite - Reference Desk - FAQs. N.p., n.d. Web. 10 May 2015.
Lada, Charles J. "The Formation of Sunlike Stars." Science 248.4955 (1990): 564-72. Web.
"Planets." Solar System Exploration. N.p., n.d. Web. 07 May 2015
Staff, SPACE.com. "Elliptical Galaxy Facts & Definition | Space.com." N.p., n.d. Web. 10 May 2015.
"Stellar Classification." Wikipedia. Wikimedia Foundation, n.d. Web. 07 May 2015.
"The Solar System - Bob the Alien's Tour of the Solar System." The Solar System - Bob the Alien's Tour of the Solar System. N.p., n.d. Web. 07 May 2015.
"Types and Classification of Galaxies." CLASSIFICATION. N.p., n.d. Web. 10 May 2015.
"ESA - Space for Kids - Our Universe - The Big Bang." ESA - Space for Kids - Our Universe - The Big Bang. N.p., n.d. Web. 10 May 2015.
"Hertzsprung-Russell Diagram." Hertzsprung-Russell Diagram. N.p., n.d. Web. 07 May 2015.
"Galaxy Formation." Galaxy Formation. N.p., n.d. Web. 07 May 2015.
"HubbleSite - Reference Desk - FAQs." HubbleSite - Reference Desk - FAQs. N.p., n.d. Web. 10 May 2015.
Lada, Charles J. "The Formation of Sunlike Stars." Science 248.4955 (1990): 564-72. Web.
"Planets." Solar System Exploration. N.p., n.d. Web. 07 May 2015
Staff, SPACE.com. "Elliptical Galaxy Facts & Definition | Space.com." N.p., n.d. Web. 10 May 2015.
"Stellar Classification." Wikipedia. Wikimedia Foundation, n.d. Web. 07 May 2015.
"The Solar System - Bob the Alien's Tour of the Solar System." The Solar System - Bob the Alien's Tour of the Solar System. N.p., n.d. Web. 07 May 2015.
"Types and Classification of Galaxies." CLASSIFICATION. N.p., n.d. Web. 10 May 2015.
Citing for video:
"Exploring the Big Bang Theory Video." History.com. A&E Television Networks, n.d. Web. 10 May 2015.
"Exploring the Big Bang Theory Video." History.com. A&E Television Networks, n.d. Web. 10 May 2015.