1. Hopf, E., Abzweigung einer Periodischen Lösung eines Differentialsystems. Berichten der Math.-Phys. Klasse der Sächsischen Akademie der Wissenschaften zu Leipzig, XCIV, 1?22 (1942).
2. Sattinger, D.H., Bifurcation of periodic solutions of the Navier-Stokes equations. Arch. Rational Mech. Anal. 41, 66?80 (1971).
3. Iudovich, V.I., Appearance of auto-oscillations in a fluid. Prikl. Mat. Mek. 35, 638?655 (1971).
4. Joseph, D.D., & D.H., Sattinger, Bifurcating time periodic solutions and their stability. Arch. Rational Mech. Anal. 45, 79?109 (1972).
5. Iooss, G., Bifurcation des solutions périodiques de certains problèmes d'évolution. C.R. Acad. Sci. Paris 273, série A, 624?627 (1971).