http://www.shutterstock.com/pic-24216871/stock-vector-symmetrical-floral-graphics-vector-illustration.html

http://www.architecture-student.com/architecture/interrelationship-of-symmetry-and-asymmetry-with-balance-and-harmony-in-design/

http://pezzettinoart.blogspot.com/2010/11/radial-symmetry-leaves-painting.html

http://albertdebruijn.com/home/archives/969