http://en.wikipedia.org/wiki/Bernhard_Riemann
http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Riemann.html
_ The Riemann Hypothesis (HD Long Version)
http://www.youtube.com/watch?v=MsBUTuYI62k
_ リーマン予想 - Riemann Hypothesis
http://www.youtube.com/watch?v=naF9I-CniQA