1. Artin, M and B. Mazur, On periodic points, Annals of Math. (2) 81 (1965), 82–99.
2. Birkhoff G. D., Dynamical Systems, AMS Colloq. Publ. IX, Providence, 1966.
3. Bowen, R. and O.E. Lanford III., Zeta functions of the restrictions of the shift transformation, Proc. Symp. Pure Math. XIV, 43–49.
4. Brown, Robert F., The Lefschetz Fixed Point Theorem, Scott Foresman and Co., 1971.
5. Chow, S. N., J. Mallet-Paret and J. A. Yorke, A periodic orbit index which is a bifurcation invariant, preprint.