books.google.com - William Clifford (1845-1879) was an important mathematician of his day. He is most remembered today for his invention of Clifford algebras, which are fundamental in modern differential geometry and mathematical physics. His ideas on the connection between energy and matter and the curvature of space...http://books.google.com/books/about/Mathematical_Papers.html?id=LzXW1Lj62AMC&q=Riemann's+surface&utm_source=gb-gplus-shareMathematical Papers