1. Rand RH (2012) Lecture notes on nonlinear vibrations (version 53). http://dspace.library.cornell.edu/handle/1813/28989 . Accessed 12 August 2012
2. Van der Pol B (1927) Forced oscillations in a circuit with non-linear resistance (reception with reactive triode). Philos Mag Ser (7) 3:65–80
3. Stoker JJ (1950) Nonlinear vibrations in mechanical and electrical systems. Interscience, New York
4. Andronov A, Witt A (1930) Zut Theorie des Mitnehmens von van der Pol. Arch Elektrotech 16(4):280–288
5. Minorsky N (1962) Nonlinear oscillations. Van Nostrand, Princeton