1. Andronov, A., Leontovich, E.A., Gordon, I.I., Maier, A.G. Theory of Bifurcations of Dynamical Systems on a Plane. Israel Program for Scientific Translations, Jerusalem, 1971
2. Andrews, J.F. A mathematical model for the continuous culture of microorganisms utilizing inhibitory substrates. Biotechnol. Bioeng, 10: 707–723 (1968)
3. Bogdanov, R. Bifurcation of a limit cycle for a family of vector fields on the plane. Selecta Math. Soviet., 1: 373–388 (1981)
4. Bogdanov, R. Versal deformations of a singular point on the plane in the case of zero eigenvalues. Selecta Math. Soviet., 1: 389–421 (1981)
5. Chow, S.N., Hale, J.K. Methods of Bifurcation Theory. Springer-Verlag, New York, Heidelbeg, Berlin, 1982