http://hubblesite.org/hubble_discoveries/discovering_planets_beyond/how-do-planets-form
http://www.popsci.com/scientists-grow-transplantable-hearts-with-stem-cells
http://www.huffingtonpost.com/2013/10/18/20-psychological-studies-_n_4098779.html
http://www.history.com/topics/karl-marx
http://www.iep.utm.edu/locke/#SH2a
http://www.iep.utm.edu/hobmoral/
http://www.canadashistory.ca/Magazine/Online-Exclusive/Articles/History-Idol--Tommy-Douglas.aspx
http://study.com/academy/lesson/baron-de-montesquieu-ideas-accomplishments-facts.html
http://www.infoplease.com/encyclopedia/people/owen-robert.html
http://www.sparknotes.com/philosophy/mill/themes.html
http://www.slideshare.net/Mintflame/a-summary-of-adam-smith-ideas-life-legacy/8-LEGACYFormalized_economic_thinking_presented_both
http://www.popsci.com/scientists-grow-transplantable-hearts-with-stem-cells
http://www.huffingtonpost.com/2013/10/18/20-psychological-studies-_n_4098779.html
http://www.history.com/topics/karl-marx
http://www.iep.utm.edu/locke/#SH2a
http://www.iep.utm.edu/hobmoral/
http://www.canadashistory.ca/Magazine/Online-Exclusive/Articles/History-Idol--Tommy-Douglas.aspx
http://study.com/academy/lesson/baron-de-montesquieu-ideas-accomplishments-facts.html
http://www.infoplease.com/encyclopedia/people/owen-robert.html
http://www.sparknotes.com/philosophy/mill/themes.html
http://www.slideshare.net/Mintflame/a-summary-of-adam-smith-ideas-life-legacy/8-LEGACYFormalized_economic_thinking_presented_both