University of St. Andrews (UK)
University of St. Andrews: Georg Friedrich Bernhard Riemann
This University of St. Andrews site contains biographical information as well as accomplishments of Riemann.
Science Struck
Science Struck: The Hardest Math Problem in the World
Discusses the two math problems that baffled mathematicians for ages, Fermat's Last Theorem and Riemann's Hypothesis. The latter is still unsolved.
Wikimedia
Wikipedia: Elliptic Geometry
This encyclopedia article contains a basic description of what elliptic geometry is.
Curated OER
Smithsonian Libraries: Scientific Identity: Bernhard Riemann (1826 1866)
A portrait of Bernhard Riemann from the Dibner Library of the History of Science and Technology, made available through the Smithsonian Institution's Scientific Identity Collection.