1. G. D. Birkhoff, “Nouvelles recherches sur les systèmes dynamiques,” in Collected works. Vol. 2, Amer. Math. Soc., Providence, R. I., 1950, pp. 530-659.
2. C. Conley, “Invariant sets in a monkey saddle,” Proceedings United States-Japan seminar on differential and functional equations, Edited by William A. Harris Jr. and Yasutaka Sibuya, Benjamin, New York, 1967. MR 36 #5415.
3. The retrograde circular solutions of the restricted three-body problem via a submanifold convex to the flow;Conley, C. C.;SIAM J. Appl. Math.,1968
4. On the ultimate behavior of orbits with respect to an unstable critical point. I. Oscillating, asymptotic, and capture orbits;Conley, Charles C.;J. Differential Equations,1969
5. Twist mappings, linking, analyticity, and periodic solutions which pass close to an unstable periodic solution;Conley, C.,1968