1. Huygens (Hugenii) C. Horologium Oscillatorium. Apud F. Muguet, Parisiis, France; 1673 [English translation, The pendulum clock, Iowa State University, Ames; 1986].
2. Synchronization: a universal concept in nonlinear science;Pikovsky,2001
3. The synchronized dynamics of complex systems;Boccaletti,2008
4. The theory of sound;Rayleigh,1945
5. Forced oscillations in a circuit with resistance;van der Pol;Philos Mag,1927