From Kant to Hilbert : a source book in the foundations of mathematics. Volume II

Georg Friedrich Bernhard Riemann ; Hermann von Helmholtz ; Julius Wilhelm Richard Dedekind ; Goerg Cantor ; Leopold Kronecker ; Christian Felix Klein ; Jules Henri Poincaré ; The French analysts ; David Hilbert ; Luitzen Egbertus Jean Brouwer ; Ernst Zermelo ; Godfrey Harold Hardy ; Nicolaus Bourbaki.