[1] Kerschen, G., Worden, K., Vakakis, A.F., and Golinval, J., “Past, Present and Future of Nonlinear System Identification in Structural Dynamics”, Journal of Mechanical Systems and Signal Processing, Vol. 20, pp. 505-592, (2006).
[2] Nayfeh, A.H., and Mook, D.T., “Nonlinear Oscillations”, Wiley-Interscience, New York, (1979).
[3] Strogatz, S.H., “Nonlinear Dynamics and Chaos: with Applications to Physics, Biology, Chemistry, and Engineering”, Addison-wesley, Reading, MA, (1994).
[4] Verhulst, F., “Nonlinear Differential Equations and Dynamical Systems”, Second Edition, Springer, Berlin, (1999).
[5] Rand, R., “Lecture Notes on Nonlinear Vibrations”, Cornell, New York, USA, (2003).
[6] Caughey, T.K., “Equivalent Linearization Techniques”, Journal of the Acoustical Society of America, Vol. 35, pp. 1706–1711, (1963).
[7] Iwan, W.D., “A Generalization of the Concept of Equivalent Linearization”, International Journal of Nonlinear Mechanics, Vol. 8, pp. 279–287, (1973).
[8] Rosenberg, R.M., “The Normal Modes of Nonlinear N-degree-of-freedom Systems”, Journal of Applied Mechanics, Vol. 29, pp. 7–14, (1962).
[9] Rosenberg, R.M., “On Nonlinear Vibrations of Systems with Many Degrees of Freedom”, Advances in Applied Mechanics, Vol. 9 , pp. 155–242, (1966).
[10] Rand, R., “A Direct Method for Nonlinear Normal Modes”, International Journal of Non- linear Mechanics, Vol. 9, pp. 363–368, (1974).
[11] Shaw, S.W., and Pierre C., “Normal Modes for Non-linear Vibratory Systems”, Journal of
Sound and Vibration, Vol. 164, pp. 85–124, (1993).
[12] Vakakis, A.F., Manevitch, L.I., Mikhlin, Y.V., Pilipchuk, V.N. and Zevin, A.A., “Normal
Modes and Localization in Nonlinear Systems”, Wiley, New York, (1996).
[13] Vakakis, A.F., “Non-linear Normal Modes and their Applications in Vibration Theory: an
Overview”, Mechanical Systems and Signal Processing, Vol 11, pp. 3–22, (1997).
[14] Nayfeh, A.H., “Introduction to Perturbation Techniques”, Wiley-Interscience, New York, USA, (1981).
[15] O’Malley, R.E., “Singular Perturbation Methods for Ordinary Differential Equations”,
Springer, New York, USA, (1991).
[16] Kevorkian, J., and Cole, J.D., “Multiple Scales and Singular Perturbation Methods”,
Springer, New York, USA, (1996).
[17] He, J.H., “Variational Iteration Method - a kind of Non-linear Analytical Technique: Some
Examples”, International Journal of Nonlinear Mechanics, Vol. 34, pp. 699–708, (1999).
[18] He, J.H., “Some Asymptotic Methods for Strongly Nonlinear Equations”, International Journal of Modern Physics B, Vol. 20, No. 10, pp. 1141-1199, (2006).
[19] Inokuti, M., “General Use of the Lagrange Multiplier in Non-linear Mathematical
Physics, in: S. Nemat-Nasser (Ed.) ”, Variational Method in the Mechanics of Solids,
Pergamon Press, Oxford, pp. 156-162, (1978).
[20] He, J.H., “Variational Iteration Method for Non-linearity and its Applications”, Mechanics
and Practice, Vol. 20, No. 1, pp. 30-32, (1998) (in Chinese).
[21] Finlayson, B.A., “The Method of Weighted Residuals and Variational Principles”, Academic Press, New York, USA, (1972).
[22] He, J.H., “Bookkeeping Parameter in Perturbation Methods”, International Journal of
Nonlinear Sciences and Numerical Simulation, Vol. 2, pp. 257–264, (2001).
[23] He, J.H., “New Interpretation of Homotopy Perturbation Method”, International Journal of
Modern Physics B, Vol. 20, No. 18, pp. 2561–2568, (2006).
[24] He, J. H., “Modified Lindstedt-Poincare Methods for Some Strongly Non-linear Oscillations
Part II: A New Transformation”, International Journal of Non-linear Mechanics, Vol. 37, No. 2, pp. 315, (2002).