Galois theory 3 Mathematics 3 Transactional analysis 3 Field theory 2 Mathematics -- Miscellanea. Mathematical recreations. Mathematics 2 Algebraic number theory 1 Bifurcation theory 1 Biomathematics 1 C (Computer program language) 1 Counseling 1 Fermat's last theorem 1 Geometry -History 1 Group theory 1 History 1 Mathematical recreations 1 Mathematicians 1 Mathematics -- History. Mathematicians -- History. Mathematicians 1 Mathematics --Popular works 1 Mathematics, 1 Mathematics, Humor, Mathematical recreations 1 Number theory-- Algebra-- Mathematics 1 Popular works 1 Science -- Miscellanea. Science 1 Symmetry 1 Symmetry (Mathematics) 1 Symmetry (Mathematics) Symmetrie 1