1. Conway, John H., “Effective Implications between the ‘Finite’ Choice Axioms,” inCambridge Summer School in Mathematical Logic (eds. A. R. D. Mathias, H. Rogers), Springer Lecture Notes in Mathematics 337, 439–458 (Springer-Verlag, Berlin 1971).
2. Dixon, John D., and Brian Mortimer,Permutation Groups, Springer Graduate Texts in Mathematics 163, Springer-Verlag, 1996.
3. Fine, Benjamin, and Gerhard Rosenberger,The Fundamental Theorem of Algebra, Springer-Verlag, New York 1997.
4. Gauss, Carl Friedrich,Werke, Volume 3, 33-56 (In Latin; English translation available at http://www.cs.man.ac.uk/~pt/misc/gauss-web.html).
5. Tarski, Alfred,A Decision Method for Elementary Algebra and Geometry, University of California Press, Berkeley and Los Angeles, 1951.