1. Chenciner, A. and Montgomery, R.: 1999, A Remarkable Periodic Solution of the Three-body Problem in the Case of Three Equal Masses. Northwestern University, Evanston conference on Celestial Mechanics, December 15–19.
2. Marchal, C.: 2001, ‘The family P 12 of the three-body problem. The simplest family of periodic orbits, with twelve symmetries per period’, Celest. Mech. & Dyn. Astr. 78, 279. Also ONERA TP n° 2000–2099.
3. Hohmann, W.: 1925, Die Erreichbarkeit der Himmelskörper, Oldenbourg, Munich.
4. Weierstrass, K. T. W.: 1920, Variationrechnung, Gesammelte Abhandlungen, Vol. 7.
5. Bliss, G. A.: 1946, Lectures on the Calculus of Variations, The University of Chicago Press, Chicago, pp. 1–292.