1. T. Roenneberg, S. Daan, M. Merrow, J. Biol. Rhythms 18, 183 (2003)
2. C. Huygens, Horologium oscillatorium, English translation: The pendulum clock (Iowa State University Press, Ames, 1986, 1673)
3. Y. Kuramoto, Chemical oscillations, waves, and turbulence (Courier Dover Publications, 2003)
4. V.S. Anishchenko, V. Astakhov, A. Neiman, T. Vadivasova, L. Schimansky-Geier, Nonlinear Dynamics of Chaotic and Stochastic Systems: Tutorial and Modern Developments (Springer-Verlag, New York, LLC, 2007)
5. A. Balanov, N. Janson, D. Postnov, O. Sosnovtseva, Synchronization: From Simple to Complex (Springer-Verlag, New York, 2009)