1. Galois and Group Theory
2. F. A. Cotton,Chemical Applications of Group Theory, 2nd Ed. Wiley, NY,1971.
3. H. Weyl,Symmetry, Princeton University Press, Princeton,1952.
4. Symmetry and asymmetry in aesthetics and the arts
5. See e.g.: D. Schattschneider,Visions of Symmetry. Notebooks, Periodic Drawings, and Related Work of M. C. Escher, W. H. Freeman, New York1990.