The Bifurcation of a Fixed Point to a Limit Cycle (Tabor 1989).
References
Guckenheimer, J. and Holmes, P. Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields, 3rd ed.
New York: Springer-Verlag, pp. 150-154, 1997.
Marsden, J. and McCracken, M. Hopf Bifurcation and Its Applications. New York: Springer-Verlag, 1976.
Tabor, M. Chaos and Integrability in Nonlinear Dynamics: An Introduction. New York: Wiley, p. 197, 1989.