1. Oxford Advanced Dictionary;Hornby,1974
2. Horoloquium Oscilatorium;Hugenii,1673
3. I.I. Blekman, Synchronization in Science and Technology, Nauka, Moscow, 1981 (in Russian); ASME Press, New York, 1988 (in English). ∗∗
4. Stability Theory of Synchronized Motion in Coupled-Oscillator Systems