Barack Obama

http://www.biography.com/people/barack-obama-12782369
http://es.wikipedia.org/wiki/Barack_Obama

George W. Bush

http://www.biography.com/people/george-w-bush-9232768
http://www.history.com/topics/us-presidents/george-w-bush

George H. W. Bush

http://www.biografiasyvidas.com/biografia/b/bush.htm
http://www.history.com/topics/us-presidents/george-bush

http://millercenter.org/president/bush

William J. Clinton

http://www.biografiasyvidas.com/biografia/c/clinton.htm
http://www.let.rug.nl/usa/biographies/bill-clinton/
http://www.proyectosalonhogar.com/us_presidents/clinton.htm

Ronald Reagan

http://es.wikipedia.org/wiki/Ronald_Reagan

https://www.whitehouse.gov/1600/presidents/ronaldreagan

http://www.biografiasyvidas.com/biografia/r/reagan.htm

Jimmy Carter

http://es.wikipedia.org/wiki/Jimmy_Carter
https://www.whitehouse.gov/1600/presidents/jimmycarter
http://www.cartercenter.org/news/experts/jimmy_carter.html

http://www.biografiasyvidas.com/biografia/c/carter_jimmy.htm

Gerald Ford

http://www.biography.com/people/gerald-ford-9298683

http://es.wikipedia.org/wiki/Gerald_Ford

http://www.fordlibrarymuseum.gov/grf/fordbiop.asp

Richard Nixon

http://es.wikipedia.org/wiki/Richard_Nixon
https://www.whitehouse.gov/1600/presidents/richardnixon

http://www.history.com/topics/us-presidents/richard-m-nixon

Lyndon B. Johnson

https://www.whitehouse.gov/1600/presidents/lyndonbjohnson
http://www.lbjlib.utexas.edu/johnson/archives.hom/biographys.hom/lbj_bio.asp
http://www.history.com/topics/us-presidents/lyndon-b-johnson
http://www.biografiasyvidas.com/biografia/j/johnson.htm

John F. Kennedy

http://www.biografiasyvidas.com/monografia/kennedy/

http://www.jfklibrary.org/JFK/Life-of-John-F-Kennedy.aspx

Dwight D. Eisenhower

http://www.ecured.cu/index.php/Macartismo

http://www.biografiasyvidas.com/biografia/e/eisenhower.htm

http://presidenteseeuu.blogspot.com/2009/10/dwight-eisenhower.html

Harry S. Truman

http://www.google.com.pr/url?sa=t&rct=j&q=harry%20s%20truman&source=video&cd=1&cad=rja&uact=8&ved=0CBwQtwIwAA&url=http%3A%2F%2Fwww.biography.com%2Fpeople%2Fharry-s-truman-9511121&ei=BLdHVfeGHcqngwT58ICABg&usg=AFQjCNFpOC7kvUGOn8ejSYDm4drtxXHf4Q&sig2=nVAKcGGPpdyVOQPudICv-w&bvm=bv.92291466,d.cWc

http://www.biografiasyvidas.com/biografia/t/truman.htm

http://www.history.com/topics/us-presidents/harry-truman