Frege
Gottlob Frege, Stanford Encyclopedia of Philosophy
Frege's Logic, Theorem, and Foundations for Arithmetic, Stanford Encyclopedia of Philosophy
Russell
Bertrand Russell, Stanford Encyclopedia of Philosophy
Writings by Bertrand Russell: Electronic Texts on the WWW (Writings by Russell: electronic texts)
Moore
George Edward Moore, Stanford Encyclopedia of Philosophy
George Edward Moore
Philosopher of the Month
Wittgenstein
Ludwig Wittgenstein, Stanford Encyclopedia of Philosophy
Papers of Ludwig Wittgenstein (1889-1951), Philosopher (Wittgenstein's papers at Trinity College, Cambridge)
Wittgenstein Links